Abstract: Focuses on the negotiations that led to the institutionalization of closer cooperation or flexible integration, i.e. the possibility for a number of member states to cooperate more closely in specific areas using the institutional framework of the Union. Flexibility is examined because it is an important legal and political issue, influencing all aspects of Union activity in the long term. Although the notion of flexibility is not new to the Union, the Amsterdam Treaty provides the first institutionalization of this concept as a basic principle in the Treaties. This chapter tries to determine how the subject was approached in the negotiations. To assess the outcome of the flexibility clauses in the Amsterdam Treaty and the different stages of the negotiations on flexible integration, the chapter is divided into four parts: first, a description of the flexibility clauses in the Treaty; second, the agenda-setting stage, which lasted from June 1994 to June 1996; third, the drafting stage, which ran from July 1996 to December 1996; and finally, the negotiating stage, which lasted from January 1997 to October 1997.

Keywords: agenda-setting, Amsterdam Treaty, clauses, cooperation, drafting, European Union, flexible integration, institutionalization, member states, negotiation,