This chapter charts how irregular migration was first identified in France and the UK as a social problem requiring state intervention. Building on theories of information processing, it explores the filters through which each government scanned their political and operational environment to identify and frame the issue. In the UK, a political preoccupation with limiting overall numbers of Commonwealth migrants led to measures to penalise ‘evasion of control’ in the late 1960s. In France, concerns about 'clandestine work' prompted a focus on irregular labour in 1970s, which built on earlier security priorities tied to the Algerian War. By locating the emergence of the issue in historical and cross-national context, our analysis highlights the contingent and selective nature of state knowledge production about irregular migration.

The 1980s and 1990s saw a phase of increasing intergovernmental cooperation between European countries, culminating in Schengen and EU cooperation on immigration. This sharply exposed the divergence of migration control across European countries, triggering both ‘learning effects’ as countries adapted domestic legislation on asylum and borders, and ‘compensatory effects’ to mitigate the loss of internal Schengen border controls. Yet rather than leading to convergence, national systems of internal migration control remained surprisingly enduring. The chapter shows how the persistence of these divergences made arrangements on Schengen and free movement vulnerable to political shocks such as the 2015 refugee crisis and Brexit.

Regularisation has been part of the French state's policy response to immigration since World War II. Since the end of labour migration in the mid-1970s, one of the key routes to legal immigration in France has been through regularisation by local administrations. These generally discreet practices reveal an intimate knowledge on the part of street-level bureaucrats of this supposedly invisible population. Alongside this generally low-key process, the French state has also organised more visible ‘mass regularisations’, notably in 1981, 1991 and 1998. This chapter explores the political dynamics shaping the French government’s approach to both ‘exceptional’ and ongoing regularisation. Through archival and interview data, it shows how the French authorities at the local and national level developed an array of strategies to manage the visibility of its regularisation policies.