He was elected as a candidate for Mitterrand's Convention of Republican Institutions, part of the Federation of the Democratic and Socialist Left electoral coalition, in the legislative election of 1967 against Alexandre Sanguinetti, Minister of Veterans and War Victims in the third Pompidou government under President de Gaulle.
In 1986, he entered the Senate in 1988 and became President of the Socialist Group until his retirement in October 2004.