Belgium has a long tradition of engaging ministerial cabinets in policymaking. As a matter of fact, its ministerial cabinet system is one of the oldest in the world, and one of the closest to the ideal, the other exemplar being the French system. Ministerial cabinets (MCs) are not to be confused with cabinets of ministers. The latter refer to the core executive, in particular members of government, while the former are an extension of the core executive, located at the structural interface between politics and administration. Walgrave and colleagues (2004, p 21) define ministerial cabinets as ‘a staff of personal advisers who are hired when a minister takes office and are not part of the administrative hierarchy’. These personal staff members act as the ‘minister's private council’ (Walgrave et al, 2004, p 7). They ‘assist the minister in identifying and formulating problems, in outlining policy, and in everyday decision-making’ (Walgrave et al, 2004, p 21).

Such ministerial offices and staff exist in other countries too. However, ministerial cabinets differ significantly from ministerial offices in non-ministerial cabinet systems. First, they are relatively large, comprising a mixture of civil servants and external appointees who work as advisers. The latter, at least, are expected to be sympathetic to the minister's views. Second, the minister has discretionary authority to organise and recruit the cabinet staff, including civil servants whose political allegiances are often evident. Third, members of cabinet not only advise the minister, but also provide political direction and management to the entire ministry. They issue instructions to the ministry in the minister's name, while its leading members, who usually have the right to sign documents on the minister's behalf, often represent the minister at external events and are regarded as speaking in the minister's name both within and outside the ministry (James, 2007). Moreover, members of cabinet acting as ‘an extension of their minister’ (instead of trustee) are in a superior position in relation to senior civil servants. They constantly put pressure on administrators in order to ensure political responsiveness, at times even meddling with civil service appointments. Finally, civil servants in ministerial cabinets have the ability to pursue careers as advisers without this hindering their progression when they return to their department.