The article analyses the role of the Commission, the Parliament, and the Council in the two main legislative procedures in the European Union: co-operation and co-decision (I). We use the legislative history of some 5,000 parliamentary amendments. These procedures have been the subject of a great deal of theoretical debate. According to conventional wisdom the co-decision procedure increases the powers of the European Parliament. Revisionist approaches, however, suggest that the conditional agenda-setting powers accorded to the Parliament by the co-operation procedure are more important than the veto powers ascribed by co-decision.