2.1 The transformation and rise of Article 14 ECHR

Critical changes in the ECtHR’s approach have contributed to the transformation of the non-discrimination clause from an ancillary clause to an autonomous legal basis sustaining ECHR claims. First, the Court liberated the provision from its ‘parasitic’ existence by clarifying that a violation could occur even if there was no breach of the adjacent substantive provision. ^{Footnote 6} The resulting ‘ambit’ requirement, whose exact scope has been the subject of several studies, can thus be met in cases relating to governmental measures that promote the fulfillment of the Convention rights, even if not required by them (Gerards, Reference Gerards2013, p. 100). The Court also made it clear that the list of grounds enumerated in Article 14 ECHR is not exhaustive, recognising certain discrimination grounds not expressly listed in it. ^{Footnote 7} Pushed by a growing number of applications, the Court has increasingly decided cases under this provision. ^{Footnote 8}

Second, the Court has occasionally, though not consistently, used a conception of substantive equality in its application of Article 14 ECHR. This approach is all the more important for the protection of vulnerable people (Fraser and Honneth, Reference Fraser and Honneth2004; Fredman Reference Fredman2007; Atrey, Reference Atrey2018). In contrast to formal equality, which treats likes alike at face value (Fredman, Reference Fredman2011a), considerations of substantive equality take into account the context and material conditions in which applicants find themselves (Lavrysen, Reference Lavrysen2015, p. 33). In this vein, the Court has broadened the scope of Article 14 ECHR to encompass neutral treatment that disproportionately affects one particular group (indirect discrimination),Footnote ⁹ as well as stereotypes and stigma when they serve as the main justification for differentiation.Footnote ¹⁰ Still, the approach of the Court to the prohibition of discrimination remains somewhat hard to systematize (Gerards, Reference Gerards2013, p. 100; Arnardóttir, Reference Arnardóttir2014). In general, the application of Article 14 ECHR still is not entirely its ‘cup of tea’ as the Court frequently refuses to discuss such claims, stating instead that there is no need to rule separately on the discrimination angle of a complaint. ^{Footnote 11}

Third, the ECtHR has developed a hierarchy of grounds protected under Article 14, deeming some criteria unacceptable as a matter of principle, such as the criterion of race, ^{Footnote 12} or, in the absence of ‘very weighty’ reasons, the criterion of sex. ^{Footnote 13} The potential development of this binary standard has been identified as problematic, albeit less rigid than the ‘suspect ground’ doctrine in the US (Cousins, Reference Cousins2009, pp. 135–136).

A last important aspect related to Article 14 ECHR is that the Court has so far failed to capture instances of multiple discrimination. To address all their facets, discriminatory situations must be considered comprehensively, which may include intersecting or additive grounds. Intersectional discrimination specifically arises from ‘the combination of various oppressions which, together, produce something unique and distinct from any one form of discrimination standing alone’ (Hannet, Reference Hannett2003, p. 68; Crenshaw, Reference Crenshaw1989). This differs from additive discrimination where an individual ‘belongs to two different groups, both of which are affected by [discriminatory] practices’ (Hannet, Reference Hannett2003, p. 68). As we will see, accounting for migratory vulnerability can be crucial in such cases (for a similar perspective, see Moreno-Lax, Reference Moreno-Lax, Çal, Bianku and Motoc2021).

2.2 Article 14 ECHR in the migratory context

Despite its growing relevance and potency, Article 14 ECHR has, at best, played a marginal role in the migratory context, especially in cases concerning third-country nationals in the EU who are treated in a discriminatory manner (for instance, by being refused a residence permit or social benefits) due to their migratory circumstances. This migratory situation is traditionally linked in antidiscrimination law to grounds of nationality, residence status and, more rarely, race and ethnic origin. Only in a few cases have these specific grounds proven helpful in denouncing discrimination against migrants, and only against settled migrants. Among the ‘leading’ judgments that deploy Article 14 ECHR in a migratory context, the first was arguably the most promising. In Gaygusuz, the Court addressed the question of whether there had been discrimination against a settled Turkish migrant who had been denied an advance on his pension, even if he had continuously contributed to unemployment insurance. ^{Footnote 14} The applicant claimed a breach of his rights, among others under Article 14 ECHR in combination with Article 1 of Protocol No. 1 ECHR stipulating the right to property. The Court agreed that there was no objective and reasonable justification to exclude the applicant from said benefits. ^{Footnote 15} He had been discriminated against based on his nationality, for which the state should have put forward ‘very weighty reasons’ as justifications.

Dembour’s extensive assessment of Gaygusuz highlights the limited effect of this ruling (Dembour, Reference Dembour2012) which disappointed expectations of a far-reaching impact for the rights of migrants, not only with regard to their access to welfare systems (Dembour, Reference Dembour2015, pp. 255–256). By not elaborating on why and when discrimination based on nationality was unacceptable under the Convention, the Court left enough interpretive space to ‘rein in’ such an outcome in subsequent cases (Dembour, Reference Dembour2012, pp. 260–261). In M.S. v. Germany, for instance, the Court held that state parties could make a distinction between nationals and non-nationals in the context of pending extraditions. ^{Footnote 16} Moving past singular judgments, the Court’s approach seems to reflect the belief that a vision of full equality between nationalities and in all instances ‘does not at all correspond to our world order’ (Dembour, Reference Dembour2015, p. 258). In a few cases that followed, the Court ruled in favor of settled migrants who were refused the benefit of social rights.

In Koua Poirrez, the Court found a violation of Article 14 ECHR when a non-citizen, despite being legally resident in France and already receiving minimum welfare benefits, was denied a disability allowance. ^{Footnote 17} This outcome has since been emulated in other decisions dealing with benefits for legally settled immigrants. ^{Footnote 18} Similarly, in Ponomaryovi, two young brothers from Russia who had been living in Bulgaria since the age of six and eight, respectively, were barred from attending the last year of high school due to difficulties related to their nationality and residence status. They were found to have been discriminated against regarding their right to education under Article 2 of Protocol 1 ECHR. ^{Footnote 19}

While each of these rulings possesses its own merits and implications, the Court only infrequently recognises nationality discrimination, as evidenced in several other cases (Dembour, Reference Dembour2015, pp. 265–270; de Vries, Reference de Vries and Moritz2019, pp. 195–198). To give one example, the Court rejected a claim based on Article 14 ECHR in an Austrian case of a Serbian mother whose newborn son was taken away after birth because she was a non-citizen without a legal status. ^{Footnote 20} The ruling contrasts sharply with the aforementioned cases where the applicants all held relatively secure legal statuses, effectively making them less vulnerable. Tellingly, no ruling based on Article 14 ECHR addresses the existential dilemmas that migrants often confront due to a denial of even basic social services, deprivation of liberty, police violence, torture, inhumane and degrading reception and detention conditions, deportation, refoulement and forced labor and slavery.

The prospects of making a successful claim around Article 14 ECHR on grounds of nationality at the Court are paradoxically the highest for permanently settled migrants and the lowest, essentially negligible, for precarious migrants at risk of the gravest violations of their rights (Brouwer and de Vries, Reference Brouwer, de Vries, van den Brink, Burri and Goldschmidt2015, p. 135). Moreover, the state’s ability to differentiate ‘appears to depend on the nature of the right at stake’ (Brouwer and de Vries, Reference Brouwer, de Vries, van den Brink, Burri and Goldschmidt2015, p. 135): the Court usually respects the legislature’s policy choices when it comes to social or economic measures (such as the right to education, housing, social assistance) unless they are ‘manifestly without reasonable foundation’. This deference stems from the principle that ‘national authorities are in principle better placed than the international judge to appreciate what is in the public interest on social or economic grounds’.Footnote ²¹

This overall impression does not fundamentally change when looking at other cases, fewer in number, dealing with residence status as a potential ground of discrimination. In Bah, the Court did not find a violation of Article 14 ECHR in conjunction with Article 8 ECHR for a person who had unsuccessfully applied for assistance for housing for herself and her son. The reason was that she had not been granted refugee status but merely an indefinite leave to remain. ^{Footnote 22} The UK authorities were permitted to differentiate between persons with an unconditional leave to remain and persons with permits conditional on their ability to support themselves. ^{Footnote 23} In Anakomba Yula, by contrast, a non-national who had not regularised her residency was found to have suffered a violation of Article 14 ECHR linked to Article 6 ECHR, as she had been denied legal assistance to contest the paternity of her child’s Belgian father. ^{Footnote 24} The jurisprudential value of this case has been questioned, however, given the applicant’s status as a ‘quasi-regular migrant’ seeking assistance in the crucial matter of establishing kinship (Dembour, Reference Dembour2015, p. 272).

Strikingly, the grounds of race and ethnic origin have only played a marginal role in discrimination cases related to a migratory context. The controversial Biao case is the most notable one. The Second Section of the Court initially rejected the application of a naturalised Danish citizen of Ghanaian origin. The applicant claimed a violation of Article 14 ECHR due to being denied family reunion with his Ghanaian wife because he had lived in Denmark for only about ten of the required twenty-eight years – a requirement seemingly designed to avoid hindering family reunification for ‘native’ citizens. ^{Footnote 25} The Grand Chamber overruled the decision, siding with the applicant and pointing to the ‘disproportionately prejudicial effect on persons who acquired Danish nationality later in life’. ^{Footnote 26} It concluded that there was indirect discrimination based on ethnic origin. The fact that the applicant was a naturalised citizen, arguably the ‘apex’ of integration, might explain the Court’s willingness to recognise ethnic discrimination, a recognition that has been extremely rare in migration cases. Curiously, xenophobia and xenophobic motives have, for all intents and purposes, barely ever been addressed in the Court’s case law. ^{Footnote 27} Moreover, besides Biao, the Court has, to our knowledge, never ruled such cases on the grounds of ethnic origin and race. ^{Footnote 28} This is certainly a strange signal to be sent by the ECtHR, especially as the literature increasingly acknowledges that international and European migration laws are racialised (Achiume, Reference Achiume2022; de Vries and Spijkerboer, Reference de Vries and Spijkerboer2022). In a context where immigration status and nationality often serve as a proxy for race and ethnic origin, European and international courts seem unable, or rather unwilling, to recognise it. Does the Court intend to suggest that in Europe there have been no justiciable instances of discrimination related to xenophobia? Or, worse yet, does it imply that such instances should be considered acceptable as long as they do not undercut specific substantive guarantees? What is sure is that the present approach leaves a gaping hole in the protection system of the Convention, since vulnerable migrants, often among the most racialised, are unable to draw attention to the structural factors underlying their hardship. These factors translate, both directly and indirectly, into considerable disadvantages that are hard to justify.

Finally, it is notable that, except for Biao, which was about family reunification for a naturalised citizen, none of the immigration cases decided on the basis of Article 14 ECHR concerned denials of a residence permit. Instead, they confirm that ‘the right of an alien to enter or to settle in a particular country is not guaranteed by the Convention’. ^{Footnote 29} Neither do states have an obligation under Article 8 ECHR ‘to respect the choice by married couples of the country of their matrimonial residence and to accept the non-national spouses for settlement’. ^{Footnote 30} However, when a state enacts immigration legislation, it must do so in a manner that complies with Article 14 ECHR insofar as grounds unrelated to migration are concerned. ^{Footnote 31} In rare cases, the Court found a violation of Article 14 ECHR in conjunction with Article 8 ECHR when the granting of a residence permit was at stake, but only when these were concerned with differences of treatment between specific groups of migrants based on characteristics other than the ones related to the migratory context, such as family status or health condition. In Hode and Abdi, the Court held that the difference of treatment between, on the one hand, refugees who were married prior to fleeing their country, workers, and students and, on the other hand, refugees married after fleeing their country, was not objectively and reasonably justified. Arefusal to grant a family-based residence permit to a same-sex partner likewise breached the ECHR. ^{Footnote 32} In the famous Abdulaziz, Cabales and Balkandali case, the Court found sex discrimination against the three applicants – all with indefinite leave to remain in the UK – whose husbands had been refused permission to join them or remain with them in the UK.Footnote ³³ Finally, deciding to deny a residence permit based on an applicant’s health status (for instance, when they are HIV-positive) where they would have received one otherwise is in contravention of these provisions. ^{Footnote 34}

To conclude, the Court displays a general reluctance to consider migration cases as instances of discrimination, except in narrowly defined circumstances concerning settled and less vulnerable migrants. What is more, we do not know how many applications have never been filed due to a lack of prospects.

3.1 The principle of migratory vulnerability

The principle of vulnerability has been a part of the Court’s jurisprudence for some time (Peroni and Timmer, Reference Peroni and Timmer2013; Heri, Reference Heri2021), including under Article 14 ECHR (Kim, Reference Kim2021; Arnardóttir, Reference Arnardóttir2017). Its current usage, however, is largely unsuitable for immigration cases (Baumgärtel, Reference Baumgärtel2020). This section summarises the argument, detailed further in our previous works, that the Court should consider an alternative (and more nuanced) notion of ‘migratory vulnerability’ to better capture these realities (Baumgärtel, Reference Baumgärtel2019 and Reference Baumgärtel2020). Such a refined conception would enable and indeed require the ECtHR to reassess its approach to Article 14 ECHR in migration cases on a principled and foreseeable basis.

To understand both the inspiration and the need for a legal concept of migratory vulnerability, it is useful to compare the conceptions of vulnerability in scholarship and the practice of the Strasbourg Court. Fineman, in her seminal contribution ‘The Vulnerable Subject’, introduces vulnerability as a response to the shortcomings of traditional notions of equality, especially formal equality, which grounds the reasons for inequality in ‘identity categories’ that separate and potentially stigmatise people, and obscure the underlying structural conditions, such as disparities in wealth and power (Reference Fineman2008). Fineman suggests that vulnerability, as a universal and ‘socially embedded’ heuristic, may succeed where equality falls short, because it captures the concrete yet differing expressions of inequality in different cases and situations (Fineman, Reference Fineman2017, p. 145).

The approach of the ECtHR, by contrast, has been to incrementally congeal individual experiences into ‘categories’ of vulnerabilities that are essentially ‘group-based’ (Baumgärtel, Reference Baumgärtel2020, p. 17). Across different issue areas, the group-based vulnerability notion has proven useful for the Court’s work (Peroni and Timmer, Reference Peroni and Timmer2013; Besson, Reference Besson and Burgorgue-Larsen2014, pp. 80–81). Originally used in relation to the Roma minority, ^{Footnote 35} the concept has gradually expanded to other groups, such as people with intellectual disabilities (Peroni and Timmer, Reference Peroni and Timmer2013, p. 1057), ^{Footnote 36} people living with HIV, ^{Footnote 37} and asylum seekers. ^{Footnote 38} The Court has even developed a line of case law regarding what it considers ‘particularly vulnerable migrants’, ^{Footnote 39} such as migrant children in detention (Heri, Reference Heri2021, pp. 94, 98). ^{Footnote 40} Yet, this group-based approach is of limited use in the migratory context, which is characterised by a ‘multiplication of difference’ due to the proliferation of legal statuses carrying various ‘packages of rights’ (Nash, Reference Nash2009, p. 1080). Legal statuses are not only numerous but also largely void of innate qualities: persons with the ‘same’ status may have very different experiences depending on the country, region, or city (see Baumgärtel and Oomen, Reference Baumgärtel and Oomen2019), as well as the moment in time they find themselves in. ^{Footnote 41} Moreover, given the artificial nature of status-based categories like asylum seekers, it is easy to object to the idea that status-holders are experiencing vulnerabilities and instead contend that all of these are the acceptable expression of a state’s prerogative to control migration (Baumgärtel, Reference Baumgärtel2020, pp. 21–22).

The principle of migratory vulnerability aims to avoid these shortcomings of the group-based approach, while also going beyond an individual understanding of vulnerability, ^{Footnote 42} which loses sight of the underlying structural factors (such as xenophobic attitudes, institutional biases, and spatial differentiations). It constitutes, in a way, a middle ground between the two approaches to avoid their respective pitfalls. Following Fineman, migratory vulnerability adds the ‘transitory and situational adjective’ to describe a characteristic shared by all vulnerable migrants varying extents spatially and temporarily – until they either return or obtain permanent residency (Baumgärtel, Reference Baumgärtel2020, pp. 21–22). Crucially, these characteristics are ‘socially induced rather than innate but nonetheless real’ (Baumgärtel, Reference Baumgärtel2020, pp. 21–22). Capturing the lived experience of migrants is achieved by replacing set ‘identity’ categories with a systematic analysis of social processes. Legal status categories, while certainly relevant to the factual context, cannot serve as a crutch to designate vulnerable groups. Rather, the determination of migratory vulnerability would, in each specific case, be based on factual information provided by international organisations, NGOs, scholars, and other reliable sources attesting to the specific situation confronting the (allegedly) vulnerable migrant. Unlike a purely individual assessment of vulnerability, this approach still recognises the link to structural causes, notably migration control and the ‘route causes’ of displacement (Grundler, in this issue), that underlie every situational expression of migratory vulnerability. Conceptually, this emphasis on difference and ‘complex experiences’ within hierarchical structures is not new but resonates with, for example, anti-essentialist and intersectional approaches to anti-discrimination law (Grillo, Reference Grillo1995, p. 22). In the judicial arena, elements of such a structural yet ‘in concreto’ evaluation can already be found in the ECtHR’s landmark case of M.S.S. v. Belgium and Greece (Baumgärtel, Reference Baumgärtel2020, p. 23) – at least until the total reversal of the principle of ‘asylum vulnerability’ enunciated therein (Hudson, in this issue).

If incorporated into the Court’s legal arsenal, migratory vulnerability could prove to be a highly adaptive tool with a range of legal effects. As a principle characterised by ‘flexibility and versatility’ (Baumgärtel, Reference Baumgärtel2020, p. 27), its utility would not be limited to the immediate change of Article 14 ECHR praxis proposed here.

3.2 Migratory vulnerability as a ground of discrimination

In this section, we argue that migratory vulnerability, which designates the social processes related to the regulation of migration, ought to be recognised as a prohibited ground under Article 14 ECHR. The fact that migratory vulnerability is not an innate characteristic does not stand in the way of taking this step; the Court has made clear that prohibited grounds need not be inherent or immutable. Moreover, even though in some cases it may be related to a choice to migrate, migratory vulnerability is involuntary – an essential point to consider in the proportionality test (see Grundler, in this issue). Going a step further, we argue that in many instances, this ground could be considered a suspect one, requiring very weighty reasons for its justification. Even when it is not deemed suspect, the scrutiny it would entail is a logical necessity for human rights, given that migratory vulnerability is produced by state measures whose proportionality needs to be assessed specifically from this angle. We conclude this section by briefly addressing the relationship between migratory vulnerability and intersectionality.

Could migratory vulnerability become a ground to make a claim under Article 14 ECHR? The answer, in principle, should be yes, since it is an ‘open-ended clause’ that allows for criteria other than those specified therein to be invoked (Gerards, Reference Gerards, Schiek, Waddington, Droshout and Bell2007). ^{Footnote 43} However, for there to be a violation, a difference in treatment must occur based on an ‘identifiable’ characteristic or ‘status’. ^{Footnote 44} While the open-ended character of this provision lacks clear and consistent interpretation in its case law (Cousins, Reference Cousins2009; Gerards, Reference Gerards2013; Arnardóttir, Reference Arnardóttir2014), the ECtHR has recognised a large set of grounds, such as the condition of being a prisoner, ^{Footnote 45} including the length and kind of a prison sentence, ^{Footnote 46} as well as holding fishing rights in different areas, as relevant to the Article 14 ECHR assessment. ^{Footnote 47} Migratory vulnerability, as a ground, transcends homogenous groups since it seeks to avoid any determinative affiliations. It thus goes beyond the legal status to encompass different kinds of migratory realities and does not denote a particularly vulnerable sub-group within a larger identity group. ^{Footnote 48} Crucially, however, it is not a purely individual characteristic either, but foregrounds the social processes related to the regulation of migration. In short, migratory vulnerability constitutes a constructed but identifiable characteristic that relates to situational vulnerability (Kim, Reference Kim2021, p. 625) shared by others. ^{Footnote 49}

Migratory vulnerability serves as a basis for and is reinforced by social prejudice and stigma (Solanke, Reference Solanke2019, p. 10). ^{Footnote 50} These are ingrained in social, political, or institutional practices. Migratory vulnerability captures the lived experience of those possessing this characteristic and replaces a premeditated set of ‘identity’ factors with an investigation of underlying social processes. In this sense, it should be considered as a viable, if somewhat atypical, ground for examination under Article 14 ECHR.

Judicial practice has long debated whether Article 14 ECHR violations require a ‘personal’ characteristic ‘in the sense of being immutable or innate to the person’, ^{Footnote 51} or whether the individual is responsible for her situation (Fredman, Reference Fredman2011b, pp. 579–580). The ECtHR has by now confirmed that discrimination can occur on the basis of grounds that are not inherent or immutable. ^{Footnote 52} Still, the question of whether a personal characteristic results from choice is essential to determining whether a ground is suspect and subject to a ‘very weighty reasons’ test, which implies a very narrow margin of appreciation of the state concerned (Gerards, Reference Gerards and Balboni2017). This decision significantly impacts the scope and the nature of the ECtHR’s control. ^{Footnote 53} For instance, as regards immigration status, the ECtHR judged in Bah that, ‘[g]iven the element of choice involved … while differential treatment based on this ground must still be objectively and reasonably justifiable, the justification required will not be as weighty as in the case of a distinction based, for example, on nationality’. ^{Footnote 54} This reasoning reflects a broader trend to blame migrants for their own conduct in order to forfeit their most basic rights (Carrera, Reference Carrera2020), which reinforces their situational vulnerability.

To reiterate, migratory vulnerability is not an innate characteristic but mutable and likely to evolve over time and in different contexts. However, even if immigration status can be described as encompassing a choice dimension (although this, too, can be debated; see van Hear, Bakewell and Long, Reference Van Hear, Bakewell and Long2018; Crawley, Reference Crawley2010; Grundler, in this issue), the vulnerabilities linked to a migratory background and social processes of exclusion cannot, logically, be described as voluntary. Migrants have no say over the form and extent of migration control, which also varies per state, and would undoubtedly prefer not to be subjected to it. Moreover, it would be illusory to argue that migrants can anticipate all the negative situations that they will encounter. Social stratification perpetuated by migration control entails numerous unintended but harmful consequences (see the notion of ‘consequential vulnerabilities’ as proposed by Grundler in this issue), such as the entrenchment of racism and xenophobia among significant portions of the population (Baumgärtel, Reference Baumgärtel2020, p. 20).

Should migratory vulnerability then be designated as a suspect ground? The answer to this question is not as straightforward. To recall, grounds found to be suspect in some instances are not always regarded as suspect and, as a result, do not always necessitate a ‘very weighty reasons’ test. Gerards suggests that suspectness ‘is a complex notion, which covers a variety of factors and rationales’ (Gerards, Reference Gerards and Balboni2017). If migratory vulnerability is recognised as a prohibited ground, it would not a priori require very weighty reasons for justification – at least not on a principled basis, as it does not qualify as an immutable trait like sex or race. However, in a substantive number of cases, it could be argued that stereotyping and stigmatisation based on migratory vulnerability and cases of invidiousness associated with it (such as the examples discussed below) warrant, nonetheless, a ‘very weighty reasons’ test. More specifically, migratory vulnerability could rise to the level of a suspect ground when specific facts display a differentiation based on ‘irrational motives’ or where they promote an image of migrants as ‘different, second-rate and inferior’ (Gerards, Reference Gerards2013, p. 115).Footnote ⁵⁵ Indeed, selection criteria for migrants appear to be neutral and merit-based only at first glance (Farcy, Reference Farcy2020) and often reflect stigma-carrying attributes and negative stereotypes (de Vries, Reference de Vries and Moritz2019, pp. 206, 209). In a politically polarised context, where misrecognition is a real possibility, the line between ‘legitimate’ and ‘invidious’ differentiation is likely to be thin, requiring the Court to scrutinise the direct and indirect effects of a measure more closely. Where policies reflect illegitimate motives, the Court would need to apply a narrower margin of appreciation, just as it would for vulnerabilities other than migratory vulnerability (Peroni and Timmer, Reference Peroni and Timmer2013, pp. 1080–1081). ^{Footnote 56}

Even if not inherently suspect, a difference in treatment based on the ground of migratory vulnerability would still be subject to judicial scrutiny, which is a logical necessity as migratory vulnerability is produced by state measures, especially when it involves a right for which the margin of appreciation is narrower (as seen in Ponomaryovi, where the right to education was at stake). ^{Footnote 57} Even without a presumption of ‘suspectness’, the Court may take into account factors ‘that are normally relevant to determining the margin of appreciation, such as the European consensus argument or the “better placed” argument, as well the weight of what is at stake for the individual’ (Gerards, Reference Gerards and Balboni2017). ^{Footnote 58}

Consideration should also be given to the interplay between migratory vulnerability and the intersectional approach (Crenshaw, Reference Crenshaw1989; Hannett, Reference Hannett2003; Moreno-Lax, Reference Moreno-Lax, Çal, Bianku and Motoc2021). Distinguishing migratory vulnerability from other grounds, even when they intersect, is vital, as none of these ‘traditional’ grounds fully captures the structural vulnerability that can result from a migratory situation. Migratory vulnerability also does not constitute a case of multiple discrimination in itself, if we consider migration control as a separate and autonomous driver of civic stratification processes. However, in many cases, it can intersect with or add to other grounds, such as gender or race, and can, from this perspective, constitute an element in cases of intersectional or additive discrimination.

3.3 Applying the comparator test to situational traits

One important but also complex aspect in Article 14 ECHR jurisprudence concerns the application of the comparator test, particularly in migration cases (Farcy, Reference Farcy2020). When assessing the basis of nationality, migrants are usually perceived as being in a different situation than citizens (the ‘usual’ comparator), especially when they are not settled. This renders the proportionality test in antidiscrimination law irrelevant in most cases. Worse yet, when the denial of residence status is at stake, migrants simply have no relevant comparator whatsoever. Resembling the situation of pregnant women, comparisons within migrant categories would be inadequate, as they overlook the structural dimensions of migratory vulnerability, just as comparisons within and among women categories overlook the wider context of patriarchy. In essence, any approach premised on migratory vulnerability will face challenges tied to the comparator test. In this section, we argue that the Court should, therefore, abandon the comparator test in the assessment of discrimination on grounds of migratory vulnerability. This follows the suggestions of some authors regarding other grounds. Instead, we propose the Court should adopt the ‘disadvantage test’ put forward by Janneke Gerards (Reference Gerards2013).

In its review of Article 14 ECHR cases, the Court has often applied the comparator test considering that ‘only where there is differential treatment … of persons in analogous or relevantly similar positions, can there be discrimination’ (emphasis added). ^{Footnote 59} Some separate opinions have even stated that ‘comparability is the logical precondition for engaging in the exercise of examining the justification for a difference in treatment’. ^{Footnote 60} According to Judges O’Leary and Koskelo, ‘the need to demonstrate analytical rigour when it comes to the question of comparability derives, firstly, from [the Court’s] own preference under Article 14 [ECHR] for the Aristotelian principle of treating like with like’, ^{Footnote 61} which implies that only considerations of formal equality are relevant. However, this comparator approach has not been applied systematically throughout the case law of the Court. ^{Footnote 62} In fact, its use has been described as ‘underdeveloped and, at times, unclear’. ^{Footnote 63}

By contrast, Article 14 ECHR can also imply a substantive equality approach where comparability is not central or even desirable. Timmer observes that it has become ‘less important now that the Court adjudicates indirect discrimination cases increasingly often and, anyway, the Court almost never pays explicit attention to the comparability in cases that concern “suspect” classifications’ (Timmer, Reference Timmer2011, p. 719). Using a comparability test can be deceptive, especially when a substantive equality approach is needed. As Fredman explains, the comparability approach assumes a ‘universal’ individual; this comparator is usually male, heterosexual, white, healthy and Christian. This universal individual assumption creates powerful conformist or assimilationist pressures that undermine substantive equality (Fredman, Reference Fredman2011b), as the American feminist experience shows us (Goldberg, Reference Goldberg2011). In other words, a comparator approach ‘obscures what discrimination law should be about: addressing disadvantage and subordination of certain disfavored groups’, by getting stuck in in a sameness/difference ideology (Peroni and Timmer, Reference Peroni and Timmer2011). ^{Footnote 64} The Court itself departed from the comparative approach in several cases involving issues of substantial equalities, especially indirect discrimination, showing that, in some instances, this approach is inappropriate to deal with inequality related cases. ^{Footnote 65}

In this context, the comparator test appears particularly unsuitable for dealing with migratory vulnerability, which is grounded in a substantive equality approach. The aim is to identify specific exclusionary practices caused by social processes linked to the migratory trajectory and migration control, for which it might be difficult, if not impossible, to find a comparator group – considering that citizens are, by definition, free of any such constraint. Relying on a comparator would obscure the disadvantages that migrants experience due to their specific vulnerabilities that result from the many social processes behind their migratory background, which will be idiosyncratic. ^{Footnote 66} Finally, introducing a comparator in such cases would also risk creating groups of ‘deserving’ and ‘undeserving’ vulnerable migrants, whereas this ground is fluid and is likely to evolve from one situation to another (Ganty, Reference Ganty2022).

It should be noted that alternative approaches to the comparability tests have been proposed: for instance, the ‘disadvantage test’ by Gerards (Reference Gerards2013) requires applicants to prove that a rule or practice disadvantaged them in comparison to any other person or group of persons without the need to find a ‘proper’ comparator, understood as a person or group placed in a relevant similar situation. In other words, it is sufficient for the applicant to show that she has suffered a genuine disadvantage or less favourable treatment: ‘the only relevant question is if one group or person is allowed to exercise a certain right or receive a certain benefit, whilst this is not permitted for another person or group’, regardless of whether it is or is not in a similar situation (Gerards, Reference Gerards2013). The ‘disadvantage test’ is a good fit for assessing migratory vulnerability ground, as the focus is on the less favorable treatment without regarding for the other group placed in a similar situation. For instance, revisiting the previously mentioned Bah case, the disadvantage test would involve comparing the applicant – who was not given priority in the allocation of social housing due to her son’s immigration status – to any parent who is refused social housing, including British citizens. This contrasts with the narrow comparator that the Court actually applied: a ‘person who has indefinite leave to remain in the United Kingdom like the applicant, but whose child is either not subject to immigration control or has an unconditional form of leave’.Footnote ⁶⁷ In this context, the disadvantage test approach is particularly suitable to be applied to the ground of migratory vulnerability, which already encompasses the notion of disadvantage through the vulnerability assessment.

3.4 How to appraise claims including limitations and the proportionality of legitimate measures

As argued in our previous article, the principle of migratory vulnerability can serve different functions within the legal reasoning of the ECtHR; when its effects are diffuse, such as in the enlargement of the scope of Article 3 ECHR or the creation of positive obligations (Baumgärtel, Reference Baumgärtel2020), the principle mostly helps to counterbalance vulnerabilities experienced by migrants. By contrast, when it leads to a claim under Article 14 ECHR, it offers an autonomous remedy for migrants to challenge unjustifiable differentiation and exclusion processes.

Key to achieving this objective is the streamlined, three-step process of evaluating whether, in any given case, the applicant(s) suffered a violation of Article 14 ECHR based on their migratory vulnerability (Arnardóttir, Reference Arnardóttir, Brems and Gerards2013). First, it must be assessed whether claims fall within the ambit of any substantive ECHR provisions, which is a prerequisite for a successful invocation of Article 14 ECHR. The finding of a substantive violation is hereby not required (Arnardóttir, Reference Arnardóttir, Brems and Gerards2013, p. 339). The second step involves identifying the ground of discrimination, namely migratory vulnerability, as outlined above, which implies that a prima facie discrimination has occurred (as illustrated in the two examples below). Finally, an assessment of whether there are ‘objective and reasonable’ justifications for differentiation is needed, which means that states must prove a ‘legitimate aim’ as well as ‘a reasonable relationship of proportionality between the means employed and the aim sought to be realised’. ^{Footnote 68} It must be shown to be the least intrusive means in the specific situation of the person concerned. In this context, we expect state parties to easily pass the hurdle of the legitimate aim by referring to immigration control, whose significance is firmly enshrined in the case law of the ECtHR. ^{Footnote 69} Providing proof of their proportionality will be more difficult given that many (if not most) government policies in this area are never scrutinised for their actual impact, but are largely accepted based on a presumption of effectiveness that derives from a problematic paradigm of deterrence (Gammeltoft-Hansen and Tan, Reference Gammeltoft-Hansen and Tan2017; see also Moreno-Lax and Giuffré, Reference Moreno-Lax, Giuffré and Juss2019). The logical (but seldom discussed) consequence of this state of affairs is that vulnerable migrants are de facto forced to frame their claims as violations of Article 3 ECHR (the prohibition of inhumane and degrading treatment). While the latter does not imply a proportionality assessment, it creates an exceedingly high threshold for them to meet.

The activation of Article 14 ECHR in cases concerning migratory vulnerability would offer the Court an opportunity to reintroduce a sense of real universality, where migrants can at least hope to make a successful claim not only related to Article 3 ECHR but to any provision of the Convention, many of which would be ‘unlocked’ for the first time in the context of migration. State parties will be asked to justify the limitation of rights in the migration context – as stated, this is presently rarely the case (see also Dembour, Reference Dembour2015). Within the framework of Article 14 ECHR, this requires assessing the proportionality of a measure, which includes its suitability to achieve the intended goal, the possibility of attaining them through alternative, less intrusive measures, and balancing between the disadvantage suffered by the applicant against the (real, not presumed) progress made towards achieving the goal declared. Like the determination of migratory vulnerability, it would have to be determined in concreto whether this is the case based on reliable empirical information offered by national and international organisations, NGOs, and scientists (Baumgärtel, Reference Baumgärtel2020). The next section will illustrate how this can be achieved in practice with two examples.

We want to conclude by stressing that the objective assessment of justifications will be central to the evaluation of Article 14 ECHR claims. Indeed, it is ‘the natural analytical step by which courts can redeem government actions which … do not pursue or perpetuate invidious bias’ (Baker, Reference Baker2006, p. 722). The option of justifications is the (appropriate) heed that human rights law has to pay to the need for immigration control or, put more abstractly, of inclusion and exclusion into a political order. ^{Footnote 70} However, the effect of forcing states to engage in such systematic and evidence-based procedures should not be underestimated – again, it introduces human rights scrutiny where there is little to none at present.

4.1 Example 1: COVID-19 vaccinations for vulnerable migrants

The denial of COVID-19 vaccination to groups of migrants provides a paradigmatic example of how migratory vulnerability can be used to expose the discrimination and exclusion of individuals from their most basic need – protecting their health and their lives. In this context, the use of migratory vulnerability in antidiscrimination law appears to be all the more important to protect those migrants who are at the margins of society and excluded from vaccination schemes.

Making a vaccination programme widely available constitutes an international legal obligation for public authorities, as various international and European bodies have confirmed. ^{Footnote 71} The ECtHR has recognised that ‘vaccination is one of the most successful and cost-effective health interventions’. ^{Footnote 72} This echoes the World Health Organization’s position that ‘vaccines are one of the most effective tools for protecting people against COVID-19’ (WHO, 2021). At the same time, it has been well-documented that migrants in Europe, especially undocumented migrants, have been particularly impacted by COVID-19, as they are among the ‘at risk’ population due to their typically precarious health and living conditions (Bambra etal., Reference Bambra2020, pp. 1–5; Buheji etal., Reference Buheji2020, p. 220). Public authorities’ measures during the lockdown disproportionality impacted those living in cramped, unsanitary, and overcrowded accommodation (Beaunoyer etal., Reference Beaunoyer2020, pp. 1–9; Jæger and Blaabæk, Reference Jæger and Blaabæk2020, pp. 1–5). ^{Footnote 73} Workers in the informal sector, which has a high representation of undocumented migrants, have found themselves without income and lacking social protection. Amid these circumstances, COVID-19 vaccines emerged as a vital and urgent remedy to protect vulnerable migrants, who bore a higher burden of the pandemic compared to the general population.

That said, vulnerable migrants in Europe, especially (but not exclusively) undocumented migrants, have been excluded from the vaccination plans, if not explicitly, then implicitly. Many Western countries initially did not include undocumented migrants in their vaccination plans, thus removing a large number of people who are already in the shadows, de facto out of any health protection schemes (PICUM, 2021; IOM, 2021). As reported by the IOM, based on data collected between January and May 2021 (IOM, 2021), out of twenty-five countries in the European Economic Area (EEA), most regular migrants, asylum seekers and refugees had access to vaccination in practice. However, eight countries excluded undocumented migrants, and five others did not provide clear information about their policies. By March 2022, more than a year after the widespread rollout of vaccines, the situation had somewhat improved, but four EEA countries had still not, in practice, provided vaccinations to undocumented migrants. The status was unclear in another twelve countries (IOM, 2022). Moreover, out of twenty countries spanning Southeastern Europe, Eastern Europe, and Central Asia, six had effectively barred undocumented migrants from receiving vaccinations, with another five not providing clear information (IOM, 2022).

Some countries went even further to exclude regular migrants, refugees and/or asylum seekers from their vaccination plans, either explicitly or in practice. For instance, Hungary’s initial vaccination plan did not reference undocumented migrants, or foreigners in general. While vaccination later became possible for foreigners, it required an identification document such as a residence permit for non-national residents, thereby de facto excluding undocumented migrants. In Germany, the Ministry of Health stated that undocumented persons were entitled to vaccinations if they were habitually resident (PICUM, 2021). However, undocumented migrants without health insurance faced a conundrum; to get their vaccination costs covered by public authorities, they had to contact the welfare office, risking exposure to immigration authorities, as all public authorities are obliged to report back to the immigration agency (Haque and Margotinni, Reference Haque and Margottini2021; Matlin etal., Reference Matlin, Smith, Merone, LeVoy, Shah, Vanbiervliet, Vandentorren, Vearey and Saso2022). As a consequence, beyond the explicit exclusion of certain migrant groups from vaccination plans, the requirement to provide specific documents or the blurred barriers between health and immigration authorities created substantial obstacles for individuals, and hence vulnerabilities arising out of their migratory situation. The IOM has also underlined other challenges faced by undocumented and other migrants, including hurdles in online registration, financial barriers (e.g., fees for the vaccine), informational barriers, vaccine hesitancy, and mistrust in the health system. These issues can be attributed, at least in part, to the persistent experiences of discrimination encountered by migrants (Gamble, Reference Gamble1997, pp. 1773–1778; Razai etal., Reference Razai2021, pp. 1–2; Bogart etal., Reference Bogart2021, pp. 200–207).

In practice, many migrants have therefore been excluded due to vulnerabilities deriving from the administrative, legal, social, familial, and material context linked to their migratory status. Although such migratory vulnerability is likely most pronounced among those with an undocumented status, it undoubtedly impacts a wider population negatively. In such a context, an antidiscrimination approach (combining Article 14 ECHR in conjunction with Articles 2, 3 and/or 8 ECHR) appears necessary to counteract measures or omissions leading to the exclusion of these individuals. Moreover, as vaccines have become widely available throughout Europe, it is difficult to imagine any justification, including migration control, legitimising disadvantageous treatment. In essence, a ruling related to Article 14 ECHR and linked to migratory vulnerability would likely redress such disadvantages by facilitating easier access to vaccines and mandating the adoption of vaccination policies for migrants. This would include the creation of ‘firewalls’ (Crépeau and Hastie, Reference Crépeau and Hastie2015) that ensure that undocumented migrants can be vaccinated without their information being forwarded to government agencies.

4.2 Example 2: Discrimination within the ‘right to rent’ scheme in the United Kingdom

Another example of a useful potential application of the concept of migratory vulnerability can be found in the UK, where the conservative government introduced a ‘hostile environment’ policy in 2012 (Griffiths and Yeo, Reference Griffiths and Yeo2021). While not unique in Europe, this approach stands out in expressing ‘[t]he explicit intention … to weaponise total destitution and rightlessness, so as to force migrants without the right to be in the country to deport themselves, at low or no cost to the UK’ (Webber, Reference Webber2019, p. 77). Put differently, the deliberate creation of migratory vulnerabilities – and their entrenchment in law (Moreno-Lax and Vavoula, in this issue) – was openly promoted as a specific policy objective requiring little to no justification in human rights terms. The disadvantages have been arbitrary and wide-ranging, affecting social rights, such as the rights to education and health, as well as civil rights, such as the right to liberty and private and family life (Webber, Reference Webber2019, p. 77).

One aspect that has garnered much public attention and judicial scrutiny is the so-called ‘right to rent’ scheme, which requires private landlords to check the immigration status of their potential tenants. ^{Footnote 74} This policy was legally challenged at the domestic level by the Joint Council for the Welfare of Immigrants, which argued that it constituted a violation of Articles 8 ECHR in conjunction with Article 14 ECHR, as landlords were discriminating against tenants on the basis of nationality, ethnicity and race. ^{Footnote 75} The High Court initially sided with the claimants, finding that there was indeed a causal link between the scheme and what it considered proven discriminatory behaviour of landlords. ^{Footnote 76} Crucially, the ruling also stated that the government ‘failed to justify the Scheme, indeed it has not come close to doing so’ and to establish ‘a reliable system for evaluating the efficacy of the Scheme’. ^{Footnote 77} Yet, the Court of Appeal subsequently set aside the ruling. Applying a different standard to assessing the justification, it held that the measure was not intended to discriminate (migratory vulnerabilities not considered, of course), but that it ended up doing so ‘only collaterally’, due to the (mis)behaviour of the landlords. ^{Footnote 78} The Court also concluded that the scheme’s effects were ‘difficult to quantify’ ^{Footnote 79} and that its justification, therefore, derived simply from the ‘legitimate objective of the statutory provisions … to support a coherent immigration system in the public interest’. ^{Footnote 80}

With the case still under review with the UK Supreme Court, legal outcomes would change with the application of the principle of migratory vulnerability. Rather than seeing instances of discrimination as ‘entirely coincidental’, ^{Footnote 81} a focus on migratory vulnerability reveals that the effects of the ‘right to rent’ scheme are not isolated to people without legal residency. Rather, they are situational, dispersed among a wider population of actual and supposed immigrants as well as individuals with a migratory background – even if they are (allegedly) not the target group. The reason for this diffuse effect is that the implementation is ‘outsourced’ to landlords, private persons who usually lack the required expertise in human rights and migration law (Williams, Reference Williams2020, p. 239). Without measures to the contrary, possibilities to redress any denial of rights are also limited in practice, as critics have argued from the outset (Williams, Reference Williams2020). Once empirically identified as creating migratory vulnerabilities for a heterogenous population (Williams, Reference Williams2020; Grant and Peel, Reference Grant and Peel2015), the discriminatory effects of the measure challenged under Article 14 ECHR appear to fall within the ambit of Articles 8 ECHR and, even more compellingly in our view, Article 3 ECHR: homelessness and the resulting destitution can, under certain circumstances, be considered as ‘humiliating treatment showing a lack of respect for … dignity’ on the part of the responsible state. ^{Footnote 82} The fact that the UK authorities have neither proven the effectiveness of the scheme for the (legitimate) objective of immigration control nor explored alternative, less intrusive, and less arbitrary measures to achieve the same goal render it disproportionate and ultimately violative of Article 14 of the Convention.