John Prescott has confirmed that he will quit the Commons at the next general election, two months after stepping down as Deputy Prime Minister and deputy leader of the Labour Party.

He issued a statement saying that he would remain an MP for the rest of this Parliament. Last week he had dismissed speculation of plans for such an announcement as “press prattle”.

Mr Prescott, 69, is expected eventually to take a seat in the Lords, but will spend the next few months working on his memoirs, for which he has secured an advance of £300,000.

Although increasingly mocked as a marginal figure in his final period in Government, his biography has the scope to be highly sensitive because he was one of the few figures to be party to the feuding and private understandings between Tony Blair and Gordon Brown. Hunter Davies, the journalist and author who is ghost-writing the book, has promised a frank account, suggesting that it will deal with embarrassing episodes, including the Deputy Prime Minister’s two-year affair with Tracey Temple, his Whitehall diary secretary.

Mr Prescott told about 200 members of his local Labour Party in Hull East of his decision at a garden party at his constituency home on Saturday, where guests were served Chinese food. “It has been a huge privilege to represent the people of Hull East over the last 37 years. I will continue to do that until the next general election, whenever that might be,” Mr Prescott said in his statement.

Stephen Brady, his local chairman, said: “People paid tribute to his long service. It was an emotional event.”

Friends of Mr Prescott insisted that his announcement was unconnected to speculation that Mr Brown would call a snap election in October. But local Labour parties have been told to press on with selecting candidates in readiness for an autumn election if necessary.

Mr Prescott’s seat, a safe Labour constituency that he held with a majority of 11,747 in 2005, will become the subject of a fierce tussle. One of his two sons, David, is among those seeking to succeed him, which could prompt claims of nepotism. Another likely candidate is Chris Leslie, the former MP for Shipley, who is a close ally of Mr Brown and co-ordinated his campaign to become Labour leader.

Despite his reputation for gaffes and his decidedly mixed record as a minister, Mr Prescott is one of the last of a generation of colourful Labour politicians who fought their way to the top table of politics from the shopfloor via the union movement.

He began his career as a merchant seaman, famously working as a ship’s steward on Cunard liners serving drinks to wealthy passengers on Atlantic crossings.

He became an official in the former National Union of Seamen and was active in the 1966 seamens’ strike; he was in the gallery of the House of Commons when Harold Wilson attacked its leaders as “a tightly knit group of politically motivated men”. The young John Prescott was blacklisted by three shipping lines for his union activities. Having studied at Ruskin College, Oxford, he entered Parliament in 1970 as a union-sponsored MP.

Although a combative, left-wing politician, who stood twice unsuccessfully to be the party’s deputy leader in 1988 and 1992, he carved out a role urging modernisation to Labour’s working class supporters even before Tony Blair’s leadership, helping John Smith to win one-member-one-vote reforms in 1993. This became his key function as Mr Blair launched the creation of new Labour the following year, as Mr Prescott remained a loyal deputy leader for 13 years, often belligerent in private but seeing himself as a link to Labour’s traditional values.

But as a minister he left a trail of upheaval in his wake, insisting on heading a super ministry combining transport and regional government, his passions, with the environment and local government. However, he found it too large to do justice to them. The department created in his own image was broken up after four years and others were created for him, but rarely with any more success.

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