Election year, 2010. And these men want your vote

Tony Blair's spectacular U-turn over a referendum on Europe has provoked another flurry of speculation about when he will depart as Prime Minister. But he is not the only party leader whose future is under discussion and it is possible that all three main parties could have a new leader within two years.

The referendum expected in the autumn of next year could be the final act of Mr Blair's premiership, no matter what the result. But it could also bring down the curtain on Michael Howard's leadership of the Conservative Party and Charles Kennedy's term at the head of the Liberal Democrats.

When he succeeded Iain Duncan Smith in a bloodless coup last November, Mr Howard was seen by some Tories as a caretaker leader whose task would be to fight one general election and put his party in a position to win the one after that. But allies say the 62-year-old Tory leader has the taste for a longer spell in the top job.

Mr Kennedy may be much younger at 44 but he found his future under the intense media spotlight when an illness forced him to miss last month's Budget. His absence lifted the lid on the jockeying for position inside his party in the future leadership stakes.

With Mr Blair's political mortality underlined by his heart scare last year, the Labour Party looks as though it is preparing for the end of an era. Long-serving advisers depart Downing Street, ministerial colleagues become potential rivals and new alliances are formed.

Politics is an unpredictable game of musical chairs and the leadership of a party often falls into the lap of an outsider when the music stops. Here we look at who is likely to be at the helm of the three parties when Britain votes at the general election after next in 2009 or 2010.