Concerned by the emergence of Adolf Hitler in Nazi Germany, a group of left-wing politicians, led by Leon Blum, Edouard Daladier, Maurice Thorez, Edouard Herriot, Daniel Mayer formed the Popular Front in 1934. Parties involved in the agreement included the Communist Party, the Socialist Party and the Radical Party.

The parties involved in the Popular Front did well in the 1936 parliamentary elections and won a total of 376 seats. Leon Blum, leader of the Socialist Party, now become prime minister of France. Once in power the Popular Front government introduced the 40 hour week and other social reforms. It also nationalized the Bank of France and the armaments industry.

Leon Blum lost office in June 1937 but returned to power in March, 1938 until April 1938 when he was replaced by Edouard Daladier.