Gordon Brown has called for a ceasefire in the intense hostilities between himself and Tony Blair after a weekend of damaging headlines and speculation.

In a bid to present a united front both the prime minister and chancellor will appear before the New Year meeting of the parliamentary Labour Party today.

Following newspaper extracts of a new book which alleges the prime minister reneged on a repeatedly offered promise to stand down before the general election in favour of the chancellor, Brown appeared in a television interview to promise unity.

The book claims Brown told the prime minister: "There is nothing that you could say to me now that I could ever believe."

However, the chancellor told the BBC's Andrew Marr he would "not comment on gossip, books, rumours or innuendo in books", adding: "The reason is that we should not be distracted or diverted from the central set of issues facing the nation ahead.

"It is very important that we all do what we can in a unified way to ensure the election of a Labour government. That is the only motivation I have. That is my purpose in politics."

Responding, a senior Blairite told the Guardian: "Well, let us hope it is true, but it does not sit very well with what we read in the weekend papers.

"His people did not just co-operate with this account, they co-operated very closely."

Earlier, the prime minister again denied he had offered to stand down for Brown. He told Breakfast with Frost: "I've dealt with this six months ago. I said then you don't do deals over jobs like this - you don't."

Fleet Street, however, suggests the phoney war is over and predicts both players will face a difficult task in maintaining a united front as the election approaches.