Mr Paddy Devlin, who has died aged 74 in Belfast, was a trade unionist, a founding member of the SDLP and a minister in the short-lived power-sharing Northern executive of the 1970s.
Mr Devlin, who had been ill for some time and who had become almost blind, never wavered in his socialist convictions. He firmly believed the common cause of the socially and economically deprived had to transcend all religious differences.
He was born in Lady Street off the Falls Road on March 8th, 1925, but threats and violence forced him and his family to move to north Belfast in the early 1980s. He continued to live there until his death.
Despite these experiences Mr Devlin despised sectarianism from any quarter. "I've fought sectarianism all my life," he told The Irish Times in an interview in 1995. "That doesn't mean I was one-sided. I just hated it."
He recalled how he had Protestant neighbours: "We played football together as kids." Even after a spell of internment in Belfast Prison at the age of 17 for his republican activities, he was invited to play football for teams on the Shankill Road.
From 1942 to 1945 Mr Devlin was interned in Belfast Prison for IRA activities. Having received little formal education beforehand, he found the experience both educational and politicising. He read left-wing political literature and began to question, and eventually reject, the violent republican ethos.
He concluded that physical force would never solve the Irish problem. He wanted the IRA to pursue practical policies more concerned with helping people and finding them jobs and houses.
He was to remain for the rest of his life a strong critic of paramilitary violence.
In 1974 he said that the issuing of a target list by the Provisional IRA was a cold-blooded manifestation of desperation to rescue something from the debris of a four-year campaign of violence in the North.
Working first as a milkman for about £3 a week, and later at a local flour mill, he became a committed trade union activist and in 1950 joined the Irish Labour Party. At the age of 30 he won a council seat in Belfast in a straight competition with a young merchant seaman called Gerry Fitt.
In his autobiography, Straight Left, published in 1995, he described how reactionary Catholic forces generated opposition on the Falls to his non-sectarian socialist policies. He moved to the Northern Ireland Labour Party (NILP) in 1958, but again encountered religious divisions.
Nonetheless, in the Westminster election in 1964 the NILP achieved 102,759 votes while competing for 10 of the 12 seats.
In the 1969 elections to the Stormont parliament, Paddy Devlin won the Falls seat after having been involved in the expanding civil rights movement. In the face of growing unrest he, Gerry Fitt and others formed a new political grouping in 1970, intending it as a broad cross-community Labour party with policies based on the civil rights demands.
The new Social Democratic and Labour Party (SDLP) soon started to show cracks between the committed socialists and the broadly-nationalist members. In his autobiography, Paddy Devlin revealed that his differences with John Hume became more marked at that stage.
Mr Devlin was concerned about the emerging Provisional IRA, denouncing many of their violent acts as "unnecessary". In turn, supporters of the Provisionals made their antagonism to the outspoken leftwing politician quite plain by intimidation and attacks on him, his wife Theresa, and his sons.
His house and car were also regularly daubed with slogans.
After the dissolution of Stormont and the subsequent deterioration of the situation, particularly the bombings and shootings of the early 1970s, Mr Devlin and Mr Hume were involved in talks as intermediaries between the IRA and the British government, which led to a two-week ceasefire and the unprecedented secret talks in London between IRA leaders and British ministers.
The 1974 power-sharing executive at Stormont, in which Mr Devlin was minister for health and social services, failed, as did the Constitutional Convention to which he was also elected in 1975.
Following the collapse of the executive, it emerged that 11 days before it had actually broken up he had resigned because of a 25p-a-week fine imposed on a few thousand rent strikers continuing a campaign of civil disobedience against internment. He was persuaded to "freeze" his resignation, however, as the loyalist strike against the executive developed.
In 1977 he was expelled from the SDLP after complaining that the party was reducing the socialist content of its policy in favour of a more nationalist agenda. He said in 1995 that he should never have been caught up in a movement which was Catholic.
After the demise of the Convention in 1976, Mr Devlin and Mr Hume made another attempt at achieving a political settlement by engaging in private talks with the Rev Martin Smyth and Capt Austin Ardill of the UUP, but the effort failed.
Without an income when the Stormont institutions collapsed, he turned to writing to support himself and his family and contributed articles to The Irish Times and other newspapers.
In the 1981 Belfast City Council election he narrowly retained his West Belfast seat, but at that stage had to leave his home because of threats from extreme republicans.
In 1985 he failed to win a council seat in North Belfast as a candidate of the Labour Party of Northern Ireland, which he had helped form the previous year. In 1987 he was the first vice-chairman of Labour '87. In that year he campaigned in the US against the MacBride Principles on fair employment. He was also prominent in the Peace Train organisation.
He wrote a book on the fall of the Sunningdale power-sharing Executive and another on outdoor relief in Belfast in the inter-war years, as well as his autobiography.
A play of his, Strike, set in the Belfast docks, was performed at the Belfast Civic Arts Theatre in 1984.
In 1996 Mr Devlin received an honorary degree from the University of Ulster and earlier this year was awarded a CBE although, at his request, his name was kept off the published New Year's honours list. He said he accepted the honour for his contribution to trade unionism and socialism rather than for any work for nationalism.
In 1995 Straight Left won the Irish Times Literature Prize for non-fiction prose.