Brian Sedgemore was one of the characters of the House of Commons, whose biting comments and independent views are probably the reason why he was never offered ministerial office.

The 68-year-old dismissed Labour's new intake of women MPs as "Stepford wives", and once remarked of his colleague Ken Livingstone that: "I don't see why London has to suffer because he hasn't fulfilled his ambition to be party leader."

In the 1970s during his early years in Parliament he wrote gossip pieces for Private Eye, and he had a four-year career as a television journalist with Granada in the early 1980s when he temporarily lost his Westminster seat.

He is judged by the political website TheyWorkForYou.com the tenth most rebellious of the 649 MPs, frequently voting against the party line. But the issues on which his voting record is strongest are social ones, including an implacable hatred of fox hunting and foundation hospitals, and an equally vociferous support for gay rights.

Iraq and anti-terror laws, which he cited today in his resignation speech, are rated as issues on which his voting record shows he feels "quite strongly".

His prickly attitude has won him his share of criticism. The late Lord Onslow of Woking, a right-wing Tory peer, once described him as "a boil on the bottom of the Labour party".

Mr Sedgemore was born at Exmouth, Devon, in March 1937, one of three children brought up by a widowed mother, whose husband, a stoker on a merchant ship, was killed in the Second World War.

He rose above his circumstances by winning a place at grammar school, and read politics, philosophy and economics at Oxford before becoming a civil servant in the ministry of housing and local government in 1962. He qualified for the Bar at night, and became a criminal lawyer in 1966, marrying a fellow barrister, Audrey.

He joined Labour in 1968, partly in protest at the Vietnam War. He was first elected for Luton West in 1974, and four years later enjoyed his only taste of government office when he spent a year as Tony Benn's parliamentary private secretary when Mr Benn was put in charge of the Energy Department.

He had to resign from the unpaid role in 1978 when he revealed leaked Treasury papers on the exchange rate mechanism at a Treasury Select Committee. He went on to lose his seat in 1979, but returned in 1983 as MP for Hackney South and Shoreditch.

He made a name for himself as an acerbic questioner on the Treasury Select Committee. He has no entries whatsoever on the Register of Members' Interests, and his expenses claims as an MP have been moderate.

In his last speech to Parliament, in March, he raged that MPs appeared to have fallen asleep morally and gave a strong hint about his intentions to quit the party.

"They voted: first, to abolish trial by jury in less serious cases; secondly, to abolish trial by jury in more serious cases; thirdly, to approve an unlawful war; fourthly, to create a gulag at Belmarsh; and fifthly, to lock up innocent people in their homes," he said.

"It is truly terrifying to imagine what those Members of Parliament will vote for next. I can describe all that only as new Labour's descent into hell, which is not a place where I want to be."

He says that after the election, he will retreat to his five-bedroom house in the Gwaun Valley, north Pembrokeshire. He is married with one son.

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