The Committee for a Marxist International is a London-based Trotskyist tendency based on the ideas of Ted Grant and Alan Woods.

Grant was the long time leader of the Militant Tendency in the British Labour Party until many of his supporters were expelled. At that point Militant split into two factions. The majority formed Militant Labour outside the Labour Party, which subsequentially became the Socialist Party. Grant maintained that Marxists should remain within mainstream Labour, and formed the Workers International League which is better known by the name of its publication, Socialist Appeal.

In 1974, Militant and its co-thinkers from Sweden, Ireland and elsewhere around the world formed the Committee for a Workers International. The faction fight within Militant that led to the expulsion of Grant and Woods also played itself out within the CWI with supporters of the Grant minority leaving to form the CMI.

Just as the Grant and Woods led Workers International League pursues a policy of entrism in the British Labour Party, CMI groups outside Britan pursue entrism in equivalents of the Labour Party (where they exist), some Communist Parties such as those in Israel and Italy and, in some countries, progressive bourgeois parties such as the Pakistan Peoples Party of Benazir Bhutto.

The CMI has elected an MP in Pakistan (running for the Pakistan Peoples Party) but has also suffered splits in its Russian and American sections and seen the almost complete disappearance of its once large section in Mexico.

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