The Young Communist League (YCL) is the youth section of the Communist Party of Britain. Although its headquarters is based in London, the YCL has active branches across England, Scotland, and Wales. Aside from sports and social programs, the YCL heavily focuses on publishing political literature, with its own political journal called Challenge.

The Communist Party of Britain (CPB) is a communist party in Great Britain which emerged from a dispute between Eurocommunists and Marxist-Leninists in the Communist Party of Great Britain in 1988. It follows Marxist-Leninist theory and supports what it regards as existing socialist states, and has fraternal relationships with the ruling parties in Cuba, China, Laos, and Vietnam. It is affiliated nationally to the Cuba Solidarity Campaign and the Venezuela Solidarity Campaign. It is a member of the International Meeting of Communist and Workers' Parties, together with 117 other political parties. After the fall of the Soviet Union, the party was one of two original British signatories to the Pyongyang Declaration.