In 1903 there was a formal reconciliation at the Reims congress of the sections of the party, which then took the name of the Socialist party of France.
Com posed mainly of elements drawn from the Left, and dependent for a majority upon the support of the subversive groups of the Extreme Left, the formation of this cabinet gave the signal for a vast working-class movement, during which the Socialist party sought to extend its political influence by means of strikes and the organization of labor leagues among agricultural laborers and artisans.
From that time, Briand became one of the leaders of the French Socialist party.
But the acceptance of a portfolio in a bourgeois ministry led to his exclusion from the Unified Socialist party (March 1906).
Elected deputy by Marseilles in the general elections of 1881, he was at that time the sole representative of the Socialist party in the chambers.
