The Cripps mission was an attempt in late March 1942 by the British government to secure full Indian cooperation and support for their efforts in World War II. The mission was headed by Sir Stafford Cripps, a senior left-wing politician and government minister in the War Cabinet of Prime Minister Winston Churchill. Cripps was sent to negotiate an agreement with the nationalist leaders Gandhi, speaking for the Hindus, and Muhammad Ali Jinnah, speaking for the Muslims. Cripps worked to keep India loyal to the British war effort in exchange for a promise of full self-government after the war. Cripps discussed the proposals with the Indian leaders and published them. Both the major parties, the Congress and the League rejected his proposals and the mission proved a failure. Cripps had designed the proposals himself, but they were too radical for Churchill and the Viceroy, and too conservative for the Indians; no middle way was found. Congress moved toward the Quit India movement whereby it refused to cooperate in the war effort, while the British imprisoned practically the entire Congress leadership for the duration of the war.
Know more about Cripps' mission in Wikipedia
Know more about Cripps' mission in Wikipedia