By Alan Cowell

New York Times News Service

LONDON — Tony Benn, a passionate orator, prolific diarist and provocative leader of the British left who became the first peer to surrender an aristocratic title to remain in the House of Commons, died Friday at his home in west London. He was 88.

His death was announced by his family. No cause was specified.

Throughout his career, Benn was a rebellious figure. The scion of a political dynasty, he embraced a socialist position to the left of many of his colleagues in the Labour Party, particularly as it moved to the center under Prime Minister Tony Blair in the 1990s. While Britain’s political elite resisted and diluted union power, Benn championed labor union rights. While many Britons embraced the European Common Market in the 1970s, Benn opposed continued membership. And while Blair led the country to war in Iraq and elsewhere, Benn, a prominent advocate of nuclear disarmament, campaigned for peace.

In his later years, Benn abandoned mainstream parliamentary politics but continued to goad Blair about his close ties with President George W. Bush. In the dispute over Iran’s nuclear technology, Benn said in 2005, “we might be told that Britain must support Bush, yet again, because of the threat of weapons of mass destruction, thus allowing him to kill even more innocent civilians.”

A bitter opponent of the invasion of Iraq, Benn traveled to Baghdad in February 2003 to interview Saddam Hussein on behalf of Britain’s Channel Four television news — far more in the manner of a self-appointed pacifist emissary than as a conventional interviewer.

“I come for one reason only: to see whether in a talk we can explore, or you can help me to see, what the paths to peace may be,” he told the Iraqi leader, who replied in part by telling him that “Iraq has no weapons of mass destruction whatsoever.”

The journey to Baghdad was Benn’s second — he had traveled to Iraq in 1991 to plead for the release of British “human shield” hostages — and his readiness to break the mold of his party’s political orthodoxy was typical of a parliamentary career rooted in a longstanding family tradition of radicalism and public service.

Both of his grandfathers and his father had been members of Parliament. Benn himself became a legislator in the House of Commons, the seat of legislative power, in 1950 as the Labour representative of a constituency in Bristol.

His mother, Margaret Holmes, a theologian and feminist, was an early advocate of the ordination of women. His wife, the American-born Caroline Middleton DeCamp, was a close partner in his political life until her death in 2000. Shunning publicity, she was a lifelong advocate of state-funded education. He once called her “my socialist soul mate.” (The couple met in 1949 at Oxford and he proposed marriage to her nine days later on a park bench. In later years, they installed the same bench in the garden of their home in Holland Park in west London.) The political dynasty continued with Hilary Benn, one of Benn’s four children, who was minister for international development and later environment secretary in Blair’s government.

But the moment that propelled Benn to real prominence came much earlier.

In November 1960, he inherited the title Viscount Stansgate on the death of his father, William Wedgwood Benn. The elevation to hereditary nobility automatically barred him from sitting among the elected commoners in the House of Commons. His effort to reject his newly minted title became a cause célèbre.

Despite being disqualified from the ballot, he fought and won the 1961 by-election in Bristol that had been caused by his own disqualification from the Commons.

Under the laws of the time, Parliament refused to allow him to take his seat, as he was still a peer. Benn continued to campaign for the right to reject his peerage until 1963, when a Conservative government approved a law permitting the renunciation of such titles. He shed his peerage minutes after the law was passed and was subsequently known simply as Tony Benn, and sometimes by the more familiar nickname Wedgie.

For much of the 1960s and 1970s, Benn served as a Cabinet minister in the Labour government, his position cemented by radical credentials that gave him the support of unions and the left wing of the party. His jobs included postmaster general, secretary for industry, secretary for energy and minister of technology — a position in which he was an early supporter of the development of the Concorde supersonic airliner.

His manner and policies did not endear him to his political masters, notably Prime Minister Harold Wilson, who said he pursued “tomfool issues” and represented “a kind of aging perennial youth: He immatures with age.” As postmaster general, he campaigned passionately and unsuccessfully to have the image of Queen Elizabeth II removed from postage stamps.

Benn helped push the party to the left in an internal feud in the 1970s that left deep divisions, heralding 18 years in opposition until Blair shifted it to the market-friendly center in the 1990s to win back power in 1997. In 1975, Benn was among Labour Party rebels who unsuccessfully opposed Britain’s continued membership in the European Common Market in a national referendum.

He once said he moved further to the left as he aged. “He made enemies and kept enemies,” Margaret Beckett, a former Cabinet minister from the Labour Party, said Friday as tributes to Benn poured in from across the political spectrum. Prime Minister David Cameron said on Twitter, “There was never a dull moment listening to him, even if you disagreed with him.”

During Labour’s long period in opposition, Benn tried on several occasions to be elected to the party leadership but, increasingly seen as a maverick, he was unsuccessful. He was a bitter foe of the market-oriented policies of Prime Minister Margaret Thatcher, which encapsulated everything Benn opposed in the economics and practice of capitalism.

His critics accused him of dividing the party in a manner that Dennis Healey, a rival Labour politician, said risked “destroying the Labour Party as a force in 20th-century British politics.”

After an interview with Benn in July 1999, Warren Hoge of The New York Times reported: “These days Mr. Benn feels out of place in the Parliament he struggled to remain a member of and in the party he began passing out leaflets for as a 10-year-old in 1935. The boisterous Labour assemblage of union leaders, leftist ideologues and people whose workplaces were mines, shipyards and factory floors has now become a disciplined party of middle managers, suburban householders and get-ahead-minded businessmen.

“He favors increasing income taxes to fund public services, expanding the welfare state, rolling back privatization and restoring full union rights. He opposes nuclear weapons and waging war, unless it is approved by the United Nations Security Council,” Hoge wrote.