Parliamentary systems are characterised by strong links between the executive and the legislature. While the importance of executive–legislative relationships is well-known, the extent to which executive dominance affects parliamentary behaviour is hard to grasp. This study uses the recent institutional crises in Belgium to study parliamentary behaviour in the absence of a government with full powers. Cabinet formation in Belgium has proved to be protracted in recent years, leading to long periods of government formation in both 2007–2008 and 2010–2011. Such circumstances provide a unique comparison between normal situations of parliament in the presence of government, and exceptional situations of prolonged periods of caretaker government. In particular the article looks at three aspects of parliamentary behaviour that are usually linked to executive–legislative relations: legislative initiatives, voting behaviour and party unity. The general hypothesis is that prolonged periods of government formation gave parliamentarians more opportunities to influence the legislative process and more (ideological) freedom. The results show a nuanced picture: parliament became more pro-active, the salience of the government–opposition divide declined, while party unity remained as strong as ever. It is concluded that government formation processes did not lead to drastic changes in the legislative–executive relationship, but rather permitted a modest correction to the extremely weak position of parliament.