Socialist Action is a small Trotskyist group in the United Kingdom.^[1] From the mid-1980s Socialist Action became an entryist organisation, attempting to work within other organisations, with members using code names and not revealing their affiliation.^[2][3] It maintains a website but no publicly visible formal organisation.

The organisation was linked with the 2000–2008 Greater London mayoral administrations of Ken Livingstone, although Livingstone was never a member.^[2] Four of Livingstone's key advisers were Socialist Action members; all made the "top 25" in the Evening Standard's 2007 list of the most influential people in London.^[4][5] Its members have maintained leading positions in many campaigns - the National Abortion Campaign, the Campaign for Nuclear Disarmament, National Assembly Against Racism and various coalitions against the wars against Iraq, Afghanistan and Yugoslavia, for example. As a result, Socialist Action exert an influence beyond that which might be expected from so small a grouping.^{[citation needed]}

The group was founded in 1982 when the International Marxist Group entered the Labour Party and changed its name to the Socialist League. It became generally known by the name of its publication, Socialist Action, which first appeared on 16 March 1983.^[3] The group organised around the newspaper, but also had a bookshop The Other Bookshop, in Islington, as well as a printing press, Lithoprint Ltd, in Stoke Newington, which it still owns.^[3]

In September 1983, assuming that the Labour Party's actions against the Militant group would extend to Socialist Action as well, the group decided to disappear from public view, closing down the bookshop, and taking other measures to guarantee invisibility.^[3] Members were assigned pen names, and after the closure of the bookshop met in an assortment of pubs.^[3] The group adopted an entryist strategy "to protect members from any potential Militant-style purge".^[3]

By the mid-1980s, the group had around 500 members.^[3] Working with increasing secrecy in the Labour Party, often under the auspices of other apparently independent organisations, its members became supporters of Ken Livingstone and the Campaign Group of Labour MPs.

The group's character changed in a wave of splits in the mid-1980s, beginning in 1985 when a minority, led by Phil Hearse, Dave Packer, Davy Jones, and Jane Kelly formed the International Group, whose members were recognised by the International as remaining individual members. In 1987 the International Group merged with the Socialist Group to form the International Socialist Group and publish Socialist Outlook. The remaining majority of the Socialist League consisted of two currents. One, led by Brian Grogan, was part of the Pathfinder tendency led by the Socialist Workers Party (United States). The Grogan current was expelled by the Central Committee led by John Ross, and became the Communist League (UK, 1988).

The remainder of the group drew pessimistic conclusions from the fall of the Stalinist regimes in the Soviet Union and Eastern Europe. It continued to define itself as a Trotskyist group. It considers the Soviet model to have been preferable to capitalism for the working class, but it has always criticised that model for its bureaucratic and undemocratic features, accepting Trotsky's definition of the USSR as a degenerated workers' state. Socialist Action participated in the 1989 and 1990 Fourth International Youth Summer Camps but suffered another split after the 1991 World Congress. Small groups of Socialist Action members regularly resigned and joined the International Group, and its successor, the International Socialist Group, between the original split in 1985 and the 1991. At the 1991 World Congress of the Fourth International, the group was given equal status within the International with the International Socialist Group. At the 1995 world congress the ISG replaced Socialist Action as the British section.

In 1997, along with Labour Party activist Ken Livingstone, SA backed Morning Star chief executive Mary Rosser and committee member Kumar Murshid in a battle for control over the newspaper.^[6][7][8]

In 2001, SA stopped publishing its journal, also named Socialist Action, but continued to organise as a faction, for instance as the Student Broad Left.^{[citation needed]} In 2003, it played a major role in backing Kate Hudson's leadership of the Campaign for Nuclear Disarmament (CND),^[9] and a long-term CND officer alleged that, along with the Communist Party of Britain, it was becoming dominant in the organisation, in order to exert influence over the Stop The War Coalition.^[10] Some of its activists played leading roles in organising the 2004 European Social Forum.^[11]

Socialist Action was heavily involved in the publication and editorial control of Socialist Campaign Group News.^{[citation needed]}