James "Jock" Ritchie Haston (1913–1986) was a Trotskyist politician and General Secretary of the Revolutionary Communist Party in Great Britain.
Haston was a member of the Communist Party of Great Britain (CPGB). He moved to Trotskyism in the late 1930s, after splitting with the CPGB in 1934. The Paddington group, which he led, joined the Militant Group led by Denzil Dean Harber, and in 1937 when a group of South African Trotskyists appeared in London, it was Haston who moved their acceptance of membership in the Trotskyist group.
The South Africans were led by Ralph Lee (born Raphael Levy), hence they were referred to as the "Lee Group," and had been active in that country. A dispute with the Communist Party of South Africa was to follow them to Britain however, and it was alleged that Lee had stolen strike funds from a group of workers. These allegations would in time be proven to be lies, but were reported to the Militant Group by Charlie van Gelderen, an earlier immigrant from South Africa, and led to the split of those members of the group working with Lee.
By the time the truth had been established, and the International Secretariat of the Trotskyist movement had exonerated Lee, the damage had been done, and the comrades had formed a new organisation. The new group known as the Workers International League (WIL) was organised in late 1937. In its first days, the small group was led by Lee, but when he returned to South Africa in 1941 Haston became the leading figure within the growing organisation. He also formed a personal alliance with Millie Lee at this time.
In contrast to the official British section of the Fourth International, the Revolutionary Socialist League (RSL), the WIL was to experience serious growth in this period recruiting supporters from the CPGB, the RSL and from within the Labor Party. Again, unlike the official section, the WIL accepted the Fourth International Proletarian Military Policy (PMP) although not without an internal struggle that pitted a minority around Haston, Millie Lee (né Kuhn) and Sam Levy against Ted Grant and Gerry Healy. Haston emerged the victor from this factional tussle, and the PMP was adapted to the needs of the WIL.