Socialist National Defence League

The Socialist National Defence League, later renamed the National Democratic Party, was a political party in Britain. It was founded in 1915 as a split by the right-wing of the British Socialist Party, primarily over issues raised by the First World War. They supported "the eternal idea of nationality" and aimed to promote "socialist measures in the war effort".

The party included H. G. Wells and Robert Blatchford, and achieved ten MPss in the 1918 election, but moved even further to the right, and many of its members eventually joined the Conservative Party.