He became a representative of a teachers' union in the Complutense University, and in this role won a parliamentary seat for PSOE on 15 June 1977 and represented Madrid region until December 1995.
He was made Minister for Foreign Affairs on 22 July 1992, the day before the opening of the II Ibero-American conference of heads of state in Madrid, replacing the terminally ill Francisco Fernández Ordóñez.