Members of the European Parliament may publicly demand information from the Council or the Commission by issuing interpellations. Within parliamentary systems, opposition parties usually use interpellations to draw attention to presumed government failures and vie for public support. However, much less is known about how interpellations operate within a supranational structure like the EU without a clear opposition. We exploit that interpellations are signed by the authoring members and – drawing on over 1000 inquiries from the legislative term 2009-2014 – construct a social network of members of the European Parliament that support each other’s interpellations. This allows us to investigate how members and their groups and committees cooperate to control both Council and Commission. We map out the internal organization of the different groups issuing interpellations. Categorizing inquiries by topic enables us to estimate how much groups and single members have specialized areas of expertise, and how these interconnect.
