The two institutions forming the bicameral legislature of the EU, namely the Council of Ministers and the European Parliament (EP), consist of politicians coming from national parties. Thus, in theory, national parties could fulfil two important functions: First, national parties might constitute a democratic linkage between the people and EU legislators. Second, national parties could form an institutional linkage between Council and EP. However, as a prerequisite for providing these two linkage functions, national parties need to shape legislative behavior of their ministers in the Council and their Members of the European Parliament (MEPs). The present paper poses the following question: How do national parties try to influence voting behaviour of their representatives at the EU level? To answer this question, the paper uses a mixed-methods design, combining results from quantitative surveys with insights from qualitative interviews. Different strategies of national parties to control and coordinate voting behaviour of their representatives are exemplified. These strategies range from the most direct form of control (voting instructions) over more indirect ex ante and ex post control (candidate selection, monitoring or reporting requirements) to coordination mechanisms between ministers and MEPs. Approaches to influence voting behaviour of their representatives vary considerably between individual parties.
