The Socialist League was an organisation inside the British Labour Party, 1932–37, which brought together about 3000 intellectuals to try to push the Labour Party to the left.
The organisation was formed through a merger between the National ILP Affiliation Committee and the Society for Socialist Inquiry and Propaganda (SSIP). Both predecessors had been founded only recently. The SSIP was created by G. D. H. Cole in June 1931, and principally consisted of guild socialists, including Frank Horrabin and Will Mellor. Cole hoped to attract trade unionists, but although Ernest Bevin agreed to become honorary chairman, Arthur Pugh was the only prominent trade unionist to become actively involved.
The National ILP Affiliation Committee was founded by a group of Independent Labour Party (ILP) members who disagreed with their party's decision to disaffiliate from the Labour Party. Led by Frank Wise, they entered into negotiations with the SSIP about a merger, which was achieved in October 1932, forming the Socialist League. Wise was chosen as the new league's first chairman; Cole opposed this, hoping to retain Bevin. This led Cole to vote against the merger, and Bevin to disassociate himself from the league.
Unlike both predecessors, the league gained affiliation to the Labour Party. Its members included six Labour Members of Parliament: Clement Attlee, Seymour Cocks, Stafford Cripps, David Kirkwood, Neil Maclean and Alfred Salter. It gained great success at the 1932 Labour Party conference, winning votes committing the party to socialist legislation and, in particular, the nationalisation of the Bank of England and joint stock banks.
The group next moved to develop its own policy platform. This advocacy of a platform separate from that of the Labour Party alienated some of its supporters, and Cole, Kirkwood, Frederick Pethick-Lawrence, Pugh and Salter had all resigned by the end of 1933. However, Cripps came to greater prominence, and was elected as chairman that year.
In 1933 the League moved from research and propaganda to lobbying inside the Labour Party for particular policies. Its major effort, which failed, was to work with the ILP and the Communist Party for an anti-fascist "Popular Front" in 1937, with the Spanish Civil War as the mutual base. The Labour Party immediately expelled the League, and it dissolved in May 1937.
Looking to the future after victory at the polls, the Socialist League was obsessed by the fear that capitalists would fight back once they lost power. Laski repeatedly warned that socialist would have to use violence to get their way. The Socialist League demanded that a future socialist government should immediately pass an emergency powers act and establish a temporary dictatorship that would be ready to suppress the capitalist counterrevolution. The mainline Labour Party, however, believed firmly in parlamentarism at all times, and rejected any suggestion of a socialist emergency.
In 1937 its members established the Tribune magazine to support this campaign, which is still in existence to this day.