This article asks how ex ante and ex post control mechanisms structuring the involvement of national parliaments in European Union (EU) policy-formulation affect the scope of conflict and visibility of parliamentary debates. Based on democratic theory, partisan conflict and high visibility are normatively preferable. The effects of control mechanisms on these two criteria are assessed in a comparative case study of plenary debates in the Danish Folketing and Dutch Tweede Kamer on multiannual EU budgets. This study shows that control mechanisms have direct and indirect effects on the scope of conflict and visibility of debates by linking up to different phases of policy-formulation and media coverage cycles. Danish ex ante mechanisms trigger more partisan, but less visible debates, whereas Dutch ex post mechanisms stimulate highly visible, but intergovernmental debates. The findings thus present a trade-off between partisan conflict on the one hand and visibility on the other hand.