Tony Blair will "most probably" give no indication of his plans to quit Downing Street at next month's Labour Party conference, a Cabinet Office minister has said.
Jim Murphy said the Prime Minister had nothing to add to his pledge that he would give his successor "ample" time to bed in.
His comments came as one of Mr Blair's closest allies, Stephen Byers, warned that the next year would be "make or break time" for New Labour.
Mr Byers, the former transport secretary, called for an open debate about the future of the party but appealed to the Prime Minister's critics not to "turn the clock back".
Their intervention came as the Premier gears up for Labour's annual conference in Manchester next month as the party's rebels keep up their calls for his resignation.
Writing in The Times, Mr Byers said: "This will be make or break time for New Labour. The year ahead will set out Labour's priorities for the next decade and, in so doing, the post-Blair agenda."
He said next year's Comprehensive Spending Review (CSR) would be a major opportunity to set out the Government's direction after Mr Blair.
His foray into a Treasury area is likely to be seen as an appeal to allies of Chancellor Gordon Brown, who is widely regarded as Mr Blair's most likely successor.
Mr Murphy was asked on BBC Radio 4's Today programme whether he could see Mr Blair going through the conference season without giving any indication of his intentions. He said he "most probably" could.
"He wants up until the next election and he will provide ample time to his successor to establish themself as an effective Labour - New Labour - prime minister. I don't think there's much the Prime Minister can add to that," Mr Murphy said.
