Mr Blunkett, who worked closely with both men while a Cabinet minister, said the process by which the Prime Minister will stand down and endorse his Chancellor to replace him might be complete in a year, or two years at most.

Government insiders quickly sought to scotch the notion of a fixed timetable or a formal deal between the two men and tried to play down his remarks, saying that the recent improvement in relations between Mr Blair and Mr Brown was widely known.

Mr Blunkett’s remarks came in his first major broadcast interview since his second resignation from the Cabinet last November. In it he claimed that there was an “understanding” about the succession between Mr Blair and Mr Brown.

“My sense is that there is a new understanding, yes. And it is good because anybody with any ounce of understanding of politics knows that when Tony Blair and Gordon Brown work together we are a winner and when they are divided our opponents can divide us,” he told Sunday AM on BBC One.

“So good on them. And whether it is a year or two years, it actually will be a sensible process of combining the talents that we have.”

Patricia Hewitt, the Health Secretary, stuck to the official line, saying in a separate interview that Mr Blair would choose his own time to go.

But she said that the Prime Minister and the Chancellor had been united at a political session of the Cabinet early this month in telling colleagues that Labour’s response to David Cameron’s election as Tory leader must be to stick to the centre ground.

“Tony Blair has made it very clear that he will choose his own time to go, he’s not going to stand for another election and, of course, Gordon Brown is the man who everybody, rightly in my view, believes will take over as leader of the Labour Party and as the next Prime Minister,” Ms Hewitt told Sky News.

The intervention of Mr Blunkett, and his language, will be seen as unhelpful by allies of both men, conjuring up as it did the infamous pact sealed by the pair over dinner in Granita, an Islington restaurant, in 1994 under which Mr Brown stood aside to give Mr Blair a clear run for the Labour leadership.

One government source told The Times: “David doesn’t know anything about it. He was not sent out there to get that message (across).

“But David is right to say Tony and Gordon are working closely together and that augurs well for the orderly transition at a point when the Prime Minister decides to stand aside, as he said he will.”

Government sources denied separate speculation of a rift between Mr Blair and John Prescott over the Deputy Prime Minister’s criticism of the Government’s proposed schools reforms.

Mr Prescott is said by informed sources to feel that his criticisms, in an interview last year, were misinterpreted as he expressed misgivings about city academies, not the new generation of independent trust schools proposed in the education White Paper.

Although he is said to have doubts about the proposals, he has made it clear to colleagues that he would not play any part in defeating a Government Bill and will work to seek a compromise with Labour MPs un- happy at the plans.

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