The MRP became a mainstay of the Fourth Republic. It was allied with the Socialists and the Communists in the Three-parties alliance until spring 1947. Then, it joined the Third Force that brought together centre-left and centre-right parties against the Communists on the one hand and the Gaullists on the other hand. Two Christian Democrats led the cabinet: Georges Bidault (June–December 1946, October 1949-July 1950) and Robert Schuman (November 1947-July 1948, August–September 1948) who presented, as Foreign Minister, plans for what would become the European Community. Indeed, European unification was an important part of the MRP platform.