The paper overcomes the still common assumption that national governments could be understood as unitary actors in international relations. Therefore a model of national position taking is set up. The model takes especially formal and informal governmental structures into account. Following organization theory approaches, governments are modeled as collective actors, composed of national ministries/departments. These actors have their own preferences and interests in certain policies areas, as well as they have given resources available to obtain their goals. The processes are specified using comparable formal and informal structures. Hypotheses to explain the national bargaining positions are derived. A special focus lies on the factors, which affect the assertiveness of the national ministries. Relying on a unique data base from the intergovernmental conference 1996 of the European Union, the paper tests the hypotheses.