In this interview excerpt, Joseph Weyland, Permanent Representative to the European Communities from 1984 to 1991, recalls the Luxembourg Presidency of the Council of the European Union from July to December 1985 and describes the negotiations that led to the signing of the Single European Act. He also emphasises the close cooperation between the Intergovernmental Conference (IGC) and the European Commission in the drafting of this treaty, particularly regarding the number of areas where decisions could be taken by a qualified majority and the extension of the powers of the European Parliament.