His leadership, from 1970-75, was not the easiest time for the union as it coincided with Margaret Thatcher’s term as education secretary. A formidable opponent, she opposed key NUT policies such as the end of selection.

Sir Edward also faced a growing challenge from the rival National Association of Schoolmasters and had to fight many internal battles. The NUT national executive had resented the dominance of his predecessor, Sir Ronald Gould, and was determined to cut the general secretary down to size, with left-wingers attempting to vote him into early retirement in 1973.

Nevertheless, his leadership took in several significant achievements, including taking the NUT into the Trades Union Congress.

In 1972 the James Report recommended that teachers should be graduates and professionally trained, something the NUT had long advocated. And Sir Edward was leader of the teachers’ side of the Burnham pay negotiating committee when it won impressive pay rises averaging 30 per cent, after the 1974 Houghton report. Fred Jarvis, his deputy, said: “He was very methodical, very much a behind-the-scenes negotiator on some issues, but a very strong character at the same time.”

The son of a teacher, Edward Louis Britton was born on December 4, 1909, and educated at Bromley grammar, Kent, and Trinity college, Cambridge, where he read mathematics and edited the weekly Cambridge Review.

In 1931 he began a teaching career in Guildford and immediately joined the NUT. In 1951 he was appointed head of Warlingham secondary, Surrey. A “bilateral” school with two selective streams and four non-selective, the experience converted him to comprehensive education.

He became president of Surrey NUT in 1945, was elected a member of the union’s national executive in 1948 and was its national president in 19567.

In 1960 he was appointed general secretary of the Association of Teachers in Technical Institutions, which later became the National Association of Teachers in Further and Higher Education. He held the post until 1968 and took the association into the TUC.

In the mid-60s Sir Edward was influential in creating the “binary” structure of education that saw universities matched by a higher education public sector of technical and teacher training colleges, led by 30 polytechnics.

He was a talented writer, with a long-running column in the NUT weekly, The Teacher, under the pseudonym Peter Quince.

After retiring from the NUT he became an education lecturer at Sheffield university and then at Christ Church college, Canterbury. Active in the Association of University Teachers, he represented it at the TUC, becoming the only person to represent three different teaching unions at annual congress.

Sir Edward was also a vice-president of the National Foundation for Educational Research.

He received a CBE in 1967 and became the last NUT leader to be knighted in 1975. He married Nora Arnald, a Surrey schools inspector, in 1936. She died in 1991.