Cameron calls for snap poll after Blair's exit

David Cameron has challenged Labour to call a snap general election soon after Tony Blair stands down as Prime Minister next year.

The Tory leader believes Gordon Brown will succeed Mr Blair and will be tempted to call an immediate election, possibly as early as next autumn, because he is likely to enjoy a honeymoon period with the voters.

In an attempt to go on the offensive, Mr Cameron raised the stakes in his "phoney war" with the Chancellor by telling Classic FM radio that it would be right to hold a fresh election "as soon as is reasonably possible". He said Mr Blair had pledged in 2004 to serve a full term when he announced he would not fight a fourth election.

Labour does not have to hold an election until 2010 - five years after the last one - but Mr Cameron said a new leader should be put to an immediate public test.

"Tony Blair said at the last election he would serve a 'full term', so when he goes, no subsequent Labour prime minister can really in their heart claim to have a mandate. The British people thought they were electing Tony Blair. He's off. Someone new is coming. They need a mandate."

A Brown "bounce" will cause Mr Cameron problems. His critics are worried that the Tories' lead in the opinion polls has narrowed and that his modernisation project is alienating natural supporters. Tim Montgomerie, who founded the Conservativehome.com website, said: "If Brown enjoys a sustained honeymoon effect there must be a real risk members will decide the sacrifices of traditional Conservatism won't have been worthwhile."

* The Tories have an eight-point lead over Labour, according to an ICM survey for today's Guardian. It puts them on 40 per cent (up three), Labour on 32 per cent (no change) and the Liberal Democrats on 18 per cent (down four).