Members of the German parliament may force government to publicly reply to a question by issuing a written inquiry (kleine Anfrage). Because of this feature, inquiries are popular with the opposition that uses them to both criticize government and vie for popular support. However, little is known about the structures that generate these attacks. We exploit that inquiries are signed by the authoring parliamentarians and their supporters, and construct a social network of the opposition from 3608 inquiries issued in the term 2009-2013. Our approach allows us to shed light on how parliamentary groups cooperate and compete, on their inner structure and on who is ultimately responsible for seeking conflict. Categorizing inquiries enables us to estimate individuals' areas of expertise, what role expertise plays in the network and which topics evoke broad cooperation in a group and how one's position in the network relates to one's standing within the party.
