Workers' Socialist Federation - Communist Party (British Section of The Third International)

The conference was held in June 1920 but was attended only by WSF members, some local groups and independents. It agreed to form the Communist Party (British Section of the Third International) (CP(BSTI)) and voted to boycott future unity meetings. Instead, it attempted to interest the SLP in a merger. They proposed opening discussions with the Socialist Party of Great Britain and the British Section of the International Socialist Labour Party, but then withdrew, leaving the exercise a failure. However, the CP(BSTI) did gain influence in the Scottish Communist Labour Party and the tiny Communist Party of South Wales and the West of England was formed on their platform.

The BSP had meanwhile formed the Communist Party of Great Britain (CPGB). Lenin called on other communists to join the new party, and the CP(BSTI) was one of the groups covered in his work Left-Wing Communism: An Infantile Disorder. Although Workers Dreadnaught was openly critical of this pamphlet, Pankhurst attended the Second Congress of the Comintern, where Lenin personally persuaded Sylvia that her objections were less important than unity, and that it would be possible to maintain an anti-Parliamentary opposition within the CPGB. Pankhurst called a conference, inviting the English Shop Stewards' and Workers' Committee Movement, the Communist Labour Party, the Scottish Workers' Committee and the Glasgow Communist Group. She was imprisoned in September, but with the support of Willie Gallacher, all the groups at the conference bar Guy Aldred's Glasgow Communist Group agreed to merge with the Communist Party of Great Britain in January 1921.

After a period, Pankhurst was instructed to place the Workers' Dreadnaught under the control of the party, which she refused to do. In particular, she criticised the Communist Party members of the Poplar Board of Guardians for agreeing to reduce outdoor Poor Law relief, which was cited as the reason for her expulsion from the CPGB in September 1921. While the idea of democratic centralism, newly accepted as the governing principle for the CPGB, would seem to suggest that she was in breach of discipline, Labour Monthly continued as the personal organ of R. P. Dutt and even received subsidies.