Far-left politics in the United Kingdom

Far-left politics in the United Kingdom have existed since at least the 1840s, with the formation of various organisations following ideologies such as Marxism, revolutionary socialism, communism, anarchism and syndicalism. Following the 1917 Russian Revolution and developments in international Marxism, new organisations advocated ideologies such as Marxism–Leninism, Left Communism and Trotskyism.