The longest serving MP, Tam Dalyell, is to stand down from the House of Commons at the next election.
Tam Dalyell: Consistent maverick
The 71-year-old Labour MP for Linlithgow, was first elected to the Commons in 1962.
As the longest continuously serving MP he is known as Father of the House, a title he inherited from Sir Edward Heath at the 2001 General Election.
An old Etonian, Mr Dalyell has been a persistent opponent of British military campaigns, most recently in Iraq.
West Lothian Question
Mr Dalyell, whose Linlithgow constituency is due to disappear because of boundary changes, entered Parliament when Tory Harold Macmillan was prime minister.
His constituency agent Brian Fairley said of Mr Dalyell's decision to step down: "It is mainly because of his age although boundary changes are a
Mr Dalyell is well known for the so-called West Lothian Question - his prediction that devolution would fuel resentment if Scottish MPs continued to vote on matters which only affected England.
He achieved a high national profile for pursuing Margaret Thatcher over the circumstances surrounding the sinking of the Argentine battleship the General Belgrano during the Falklands conflict.
That campaign saw him suspended from the Commons for accusing ministers of lying over the affair.
His questioning over the controversial sinking helped him overcome the stigma of being sacked as shadow science spokesman for his relentless opposition to the Falklands War.
He opposed both Gulf wars and continues to be a thorn in the sides of the Labour leadership with his continued criticism of the war on Iraq.
Tam Dalyell after winning the West Lothian by-election in 1962
A dispute with Commons Speaker Michael Martin over the government's "dodgy" dossier on Iraq in February, 2003, led to him being ordered out of the House.
His was also ticked off by the Speaker of the Commons when he leaked minutes of a select committee's meeting about the Porton Down defence research establishment to a journalist.
He insisted he thought the minutes were in the public domain.
A former national serviceman who volunteered to fight in Korea but was dispatched instead to Germany, Mr Dalyell insists he is not a pacifist.
In addition to being an opposition science spokesman from 1980 to 1982, he also acted as parliamentary private secretary to cabinet minister Dick Crossman.
That experience led him to compare Lords reform to the mire that appears in Hound of the Baskervilles.
He is an old Etonian 10th baronet who ran the Conservative Association at King's College, Cambridge, before joining the Labour Party.
Last spring he was elected as the new rector of Edinburgh University, succeeding Green MSP Robin Harper, who held the post for three years.
Prime Minister Tony Blair paid tribute to Mr Dalyell's work: "Over more than four decades, Tam Dalyell has made a unique contribution to the life and work of the House of Commons.
"He has made his mark on many of the most controversial political debates of modern times, sometimes at the very centre of the controversy himself.
"Fiercely independent, Tam's persistence in pursuing causes close to his heart is legendary.
"He once said that the secret of his dogged determination was not being afraid `to be thought a bore'.
"Whatever else Tam can be accused of, throughout more than 40 years in Parliament, there can hardly have been a single Prime Minister, minister or Speaker of the House of Commons for whom life was boring whilst Tam was on their case.
"The House of Commons will be a very different place without him."