Brown 'loses faith in Blair pact'

Gordon Brown has lost hope that Tony Blair will hand him the keys to No 10, an explosive new book is to claim.

Brown's Britain, written with the co-operation of the Chancellor, will reveal that he has decided to distance himself from the Prime Minister and set out his own stall for the Labour leadership.

The revelation of the book's existence came amid fresh tensions between the two camps on the eve of tomorrow's pre-Budget report by Mr Brown.

The book will make clear a Brown premiership would scrap some of Mr Blair's plans to give private firms a greater role in running public services. And in what some will see as a dig at Downing Street's current close relationship with the US, it will also set out a concept of "Britishness".

Blairites today reacted with alarm at plans to publish the book in the new year, viewing it as a " deliberate and destructive provocation" in

the run-up to a spring general election. In a further sign of frosty relations between the two men, it also emerged today that Downing Street is actively exploring ways of allowing Mr Blair to remain as Prime Minister even if he is no longer Labour leader.

Cabinet Secretary Sir Andrew Turnbull has asked the Cabinet Office to find out whether Mr Blair could constitutionally stay in office.

This could be seen as a hint that Mr Blair, who infuriated Brownites by suddenly announcing he intends to serve a full third term, anticipates he might be ousted from the party leadership. But it may also be a purely technical measure to allow a smoother Labour leadership election.

Mr Brown's pre-Budget report is expected to set out his 10-year vision of how Britain should be run, with an emphasis on the long term that will be interpreted as his own mini-manifesto.

His plans have received a lastminute blow with a warning from the Organisation for Economic Co-operation and Development (OECD) that interest rates may have to go up four times next year to keep the economy on track.

The Paris-based think-tank said the election campaign next year would take place alongside falling house prices and pressure to put up taxes or cut public spending.

But the Chancellor is determined to defy the sceptics.

Brown's Britain has also been written with the help of his former chief economic adviser, Ed Balls. Author Robert Peston, a journalist close to the Treasury, reveals that Mr Brown no longer believes in a smooth handover of the Labour leadership as implied by 1994's so-called "Granita pact".