India's second largest trade union federation after the Indian National Trade Union Congress. The AITUC was formed by the Indian National Congress (the central organ of the independence movement) in 1920 to represent India at the International Labour Organisation of the League of Nations. During the 1920s British communists, in trying to organize trade unions, gained control of much of the federation; several opposing factions subsequently split away. The communists gained complete control during World War II but lost some popular support when they chose to support the war effort along with Britain after the Soviet Union entered the war. Since then, AITUC leaders have been split into reformist and revolutionary factions. The AITUC is affiliated with the World Federation of Trade Unions.