After the liberation of France in 1944, the SFIO had a coalition with a powerful Communist Party (which became the main left-wing party) and the Christian Democratic MRP. This alliance did not survive the Cold War. Blum proposed the construction of a Third Force with the center-left and the center-right, against the Gaullists and the Communists. However, his candidate to lead of the SFIO, Daniel Mayer, was defeated by Guy Mollet.