This thesis seeks to recount the history of the British popular front movement in the 1930s, especially its relationship to the Labour Party.

The popular front tactic, involving the unity of all anti-fascists, was first proclaimed to the world by the French communists in 1934. In the following year the tactic was officially sanctioned at the seventh Congress of the Comintern, and from then until the signature of the Nazi-Soviet Pact in 1939 communist parties throughout the world sought the formation of popular fronts.

In its British form the popular front has been neglected both by historians of the 1930s and of the Labour Party. The question why the movement should not figure prominently in the former case is easily understood. It came nowhere near to attracting the support of all anti-fascists, yet alone to overthrowing the National Government. Moreover, it was a confusing movement, and it involves analysing problematical questions. Nevertheless, the movement is of interest in the general context of the 1930s for it grew to attract considerable support, not least in the Labour Party. Indeed, the reason for the popular front's neglect in the context of the Labour Party is very difficult to comprehend. The Labour Party was by far the largest opposition party and official Labour hostility played the major part in dooming the movement as a serious challenger to the government. More importantly, the movement emphasised divisions and problems within the party which can be traced back in its history, especially to the events of 1931, and which by 1959 were posing a serious threat to the party's future.