The Sun claims today that Tony Blair is prepared to sack Gordon Brown if he stands in the way of a euro referendum.

Speaking to Radio 4 yesterday, Peter Mandelson encouraged the prime minister to back a referendum.

"In my view, the conditions of convergence necessary for entry have broadly been achieved. Most economic analysts believe we will be ready to go into the single currency in about two years if we take the decision some time over the next 12 months," he said.

The former Cabinet minister also indicated that the prime minister will know when the time has come to stand down from Downing Street.

"I don't think he's going to want to overstay his welcome. That I'm sure about.

"I think he will judge the time to go as prime minister not by how long he's been there but by how much he's achieved," he said.

In its editorial, the Sun implores the prime minister to think again.

"Today, Britain needs Blair to put his understandable pride over Iraq to one side and take on board what Gordon Brown and millions of British people are telling him. Forget about the euro, Tony", it urges.