Ernest Tate is a long-standing supporter of the reunified Fourth International, based in Canada. Born on Shankhill Road, in Belfast, Northern Ireland, he received little formal education. Tate immigrated to Canada in 1955, where he was recruited by Ross Dowson into the Canadian section of the Fourth International. By 1962, he was joint editor of the Socialist Caucus Bulletin, the newspaper of the socialist caucus of the New Democratic Party. In the late 1960s, Tate moved from North America to Great Britain to work with supporters of International to solidify the International Marxist Group, of which he became a leader. Tate and fellow Canadian Pat Brain worked side by side with Bertrand Russell in the Russell Tribunal set up to investigate US war crimes in Vietnam. The beating of Tate in 1966 by supporters of Gerry Healy was a cause célèbre within the worldTrotskyist movement. One of his recruits to the IMG was Tariq Ali. Ali described Tate as working closely with Pat Jordan, the two being the leading supporters of Pierre Frank's ideas in the UK. Tate was one of two members of the Vietnam Solidarity Campaign organising committee for the demonstration against the Vietnam war in London in October 1968 who successfully opposed a proposal to halt the march in Whitehall, which would have caused unnecessary confrontation with the police and a degeneration into violence. He was thus instrumental in ensuring that the 200,000 participants passed through London peacefully, despite dire prognostications in the press and on television. As a result, opposition to the war grew enormously in Britain at the same time as in the United States. At the time of the demonstration, The Guardian described him as "an able Ulsterman in his early thirties, with unmodishly short dark hair, the black-rimmed spectacles of an advertising executive, and a terse, direct, manner". Tate was a founder of the Leninist Trotskyist Tendency in 1973. He returned to Canada in 1969 and worked there as a machinist until his retirement. In 2014, the first volume of his memoir, Revolutionary Activism in the 1950s & 60s, was published. After reading the book, David Horowitz, who had known Tate in the 1960s when both men were anti-war activists, struck up a dialogue him, but noted that their strong political differences barred any friendship.
