Kenneth Gill was a communist trade union leader who made his name by blocking Barbara Castle’s contentious In Place of Strife proposals in 1969 when the Labour Government was keen to curb the power of the trade unions. Gill continued to be a thorn in the side of government industrial policy in the 1970s by opposing moves to limit income rises at a time when many of his union colleagues were persuaded to support the Government. In the 1980s he was a staunch advocate of equal opportunities and did much to promote the cause of women and racial minorities within the trade unions movement.

In 1974 Gill was the first communist for many years to be elected to the TUC council, attracting more than seven million votes. In the same year he became General Secretary of Tass, the union for administrative staff within the Amalgamated Union of Engineering Wokers (AUEW), holding the post until 1988. By then he had led the TUC as president from 1985-86, the turbulent year following the miners’ strike when Norman Willis was serving as TUC General Secretary.

When Tass left the AUEW grouping in 1988 and merged with the Association of Scientific, Technical and Managerial Staffs to form the Manufacturing Science and Finance Union, Gill became its chairman and stayed in the post until his retirement in 1992.

As the UK struggled through its economic difficulties in the 1970s, Gill became known as a member of the “awkward squad”, unionists whose persistent resistance to an enforced incomes policy made industrial relations with successive governments highly fraught. He remained recalcitrant even after the TUC struck a deal with the Labour Government on incomes policy in 1976, claiming that it would leave some families on the poverty line.

Yet Gill was far from being the sterotypical belligerent unionist. With a distinctive Wiltshire burr and a winning laugh, he was a man of charm and considerable powers of persuasion. Gill managed not only to enjoy a remarkable rapport with the rank and file of his union but also even those who disagreed vehemently with his politics were prepared to make exceptions for him.

The most remarkable example of this was when Frank Chapple, the right-wing electricians’ leader, who preceded Gill as president of the TUC, stated that he would not oppose him because he was likely to do a good job. Yet there was no doubt that Gill, unlike the characteristic “coalfield communist”, was a party man first and trade unionist second. Despite such challenges as the Hungarian Revolution in 1956 and the Polish Solidarity movement in the early Eighties, his loyalty to the Leninist main line never wavered.

At the same time, he spent little time getting embroiled in political intrigue either inside or outside the party. He tried to avoid taking sides in the bitter Euro-communist controversy that split the party, and although he had a low view of what he called the “outside Left” of Trotskyists and their variants, for the purposes of working with them he developed an apparently acceptable bantering style.

Kenneth Gill was born in Wiltshire in 1927, into a working-class family whose limited means meant that he could not fulfil an early ambition to become an artist. Instead, he left Chippenham Secondary School at 16 for an engineering apprenticeship, and developed a profound resentment of the way that he and his seniors were treated.

At the same time his talents were recognised and he moved on to draughtsmanship and design as soon as his apprenticeship was completed. He had been pursuaded to join the communism cause by the Welsh miner who lodged with his family during the Second World War.

He began his political career campaigning in 1945 on behalf of the local Labour candidate and by 1948 was active in both the party and the Association of Engineering and Shipbuilding Draughtsmen (later successively Data and, on merger with the engineering union, Tass).

He also had a successful career at his trade, including project work and engineering sales. In 1962 he moved to full-time union work, as district organiser for Liverpool and Ireland. In 1968 he became editor of the union journal, in 1972 deputy general secretary and in 1974 general secretary. He proved a popular general secretary of Tass although he earned the disapprobation of some members after it emerged in 1984 that he had been given a 36 per cent pay rise.

On the TUC council from the mid-70s Gill urged the congress to adopt more radical policies in support of equal opportunities. He famously told the TUC Woman’s Conference in 1976 that Britain was still a “socially backward” country despite the recent Sex Discrimination Act and that women would still need a 50 per cent pay increase to achieve parity with men. Then in 1982 he warned that black workers would form their own trade unions unless more was done to break down racial prejudice that was preventing them from being elected to union posts.

He pushed the TUC to adopt a progressive stance on international politics, and in 1988 it guaranteed the deposit for the concert at Wembley Stadium celebrating the 70th birthday of Nelson Mandela. When Mandela later visited England, he chose to meet the ANC in the TUC Congress hall.

In 1984 Gill became chairman of the People’s Press Printing Society, the co-operative that prints the Morning Star. When the paper’s editor refused to endorse the new communist party line Gill was expelled from the party.

A skilled draughtsman, Gill would while away the tedium of union meetings by scribbling cartoons of union and other political figures on the back of manifestos. He even spent desultory meetings with Margaret Thatcher and government ministers by sketching them surreptitiously. Stuck on a table with monolingual Italian relations-in-law at the wedding of his son, Gill overcame an awkward silence by sketching his new family on a table napkin. Soon a crowd begging for similar cartoons had gathered around him. Earlier this year, Hung, Drawn and Quartered — a selection of his deft political cartoons were published, each accompanied by a relevant quote and a biographical note.

In 1993, in a survey published in The Observer, Gill was voted “the Trade Unionists’ Trade Unionist”. General secretary of the Communication Workers Union, Billy Hayes, once called him “the John Lennon of the Trade Union movement”.

However, while others hailed an apparent revival in the union movement, Gill suggested it was psychologically fragile, still suffering the damage wrought by the mass unemployment of the early 1980s. Without a strong lead from the Labour government, he said, there was little hope: “You have a Labour government which is more reactionary than any Tory Government, with the possible exception of Mrs Thatcher’s. It confuses people.”

Last year he stepped down as chairman of the Cuba Solidarity Campaign, a movement protesting the US blockade on Cuba which he had helped found in 1993.

He married three times, and is survived by two sons and a daughter from his second marriage to Tess Paterson.

Ken Gill, trade union leader, was born on August 30, 1927. He died on May 23, 2009 aged 81