Emmanuelli was a member of the French Socialist Party. He has been deputy for Landes from 1978 to 1981, from 1986 to 1997 and from 2000 until his death in 2017. He served as President of the French National Assembly from 22 January 1992 through 1 April 1993. He later served as First Secretary of the French Socialist Party from 19 June 1994 through 14 October 1995.