The SWL was forced underground due to the implementation of the War Measures Act during World War II and their anti-war polemics which resulted in the group's publication being banned.
In 1955, following the expulsion of 15 supporters from the CCF, the Toronto group reconstituted itself as the Socialist Education League (SEL), pledging itself to support the election of the CCF and with the goal of supporting the growth of the CCF's left wing [REF].