In times of growing distrust between (potential) coalition partners, parliaments can play an important role in maintaining stable governments. Although often seen as weak actors, recent research suggest that parliaments are crucial arenas where coalition parties channel conflicts and hold each other accountable.Through parliamentary oversight (e.g. using parliamentary questions) majority parties can make sure that ministers execute agreed-upon compromises instead of 'drifting' to his/her party's preferential policies. This project aims to extend our knowledge of (1) the prevalence (2) rationale and (3) conditions of parliamentary oversight among majority parties. It focuses on the Belgian case, which is theoretically relevant, first, because it is a least-likely case with regards to the prevalence of intra-coalition oversight due to the collective nature of cabinet decision-making and the weak institutional position of parliament. Second, its unique split party system allows us to assess whether oversight efforts serve policy- or also vote-seeking objectives. Third, procedural differences between the Federal and Flemish parliament allow us to examine the (dis)advantageous conditions for intra-coalition oversight (with a focus on the role of committee chairs). Through large-N analyses supplemented with in-depth interviews, this project will make important contributions to literature on parliaments and coalitions, that are also highly relevant from a societal perspective.