Estelle Sylvia Pankhurst (5 May 1882 – 27 September 1960) was an English campaigner for the suffragist movement in the United Kingdom. She was for a time a prominent left communist who then devoted herself to the cause of anti-fascism.
The group continued to move leftwards and hosted the inaugural meeting of the Communist Party (British Section of the Third International). Workers' Dreadnought published "A Constitution for British Soviets" at this meeting. This was an article by Sylvia, in which she highlighted the role of Household Soviets - "In order that mothers and those who are organisers of the family life of the community may be adequately represented, and may take their due part in the management of society, a system of household Soviets shall be built up". The CP(BSTI) was opposed to parliamentarism, in contrast to the views of the newly founded British Socialist Party which formed the Communist Party of Great Britain (CPGB) in August 1920. The CP(BSTI) soon dissolved itself into the larger, official Communist Party. This unity was to be short-lived and when the leadership of the CPGB proposed that Pankhurst hand over the Workers Dreadnought to the party she revolted. As a result she was expelled from the CPGB and moved to found the short-lived Communist Workers Party.
Sylvia by this time adhered to left or council communism. She was an important figure in the communist movement at the time and attended meetings of the International in Russia and Amsterdam and also those of the Italian Socialist Party. She disagreed with Lenin on important points of Communist theory and strategy and was supportive of "left communists" such as Anton Pannekoek.