The power of legislative hot air: Informal rules and the enlargement debate in the European parliament

Integration theorists disagree over the extent to which the European Parliament can substantially influence policy‐making processes in the absence of formal agenda‐setting power. This article discusses the impact the European Parliament had on the current enlargement negotiations. Although the legislature does not yet possess the means to alter the stance of the European Council, it has tried to reverse the status quo through the use of its informal bargaining power. We argue based on a principal‐agent framework of analysis that the effectiveness of this strategy is largely a consequence of the ability to speak with one voice. The article evaluates various mechanisms to help the European Parliament build a unified position. It refutes socialisation and specialisation theories, showing that party group pressure towards a unified position overrode national concerns and constituted a necessary precondition in the development of an integrationist attitude. A statistical analysis of the pre‐bargaining positions inside the Foreign Affairs and Security Committee largely confirms the insights from qualitative interviews with participants and observers.