In March 1989 he became a municipal councillor in Mulhouse. At the same time, Waechter's 1988 campaign manager, Jean-Louis Vidal, became the first Green elected in Paris, illustrating the Greens were viable in major cities. Three months later, in June 1989, the list Waechter led for European elections obtained 10.8% of the vote (1,922,945 votes) and 9 seats, the best result ever obtained by the Greens in EP elections until 2009. He then became a Member of the European Parliament (MEP). In March 1992, the Greens and Ecology Generation (led by Brice Lalonde) each obtained about 7% of the vote, and Waechter became a councillor in the Alsace Regional Council.