There are "tensions" between Tony Blair and Gordon Brown, a senior cabinet minister admitted yesterday amid reports that relations between the two were increasingly bitter.
Northern Ireland Secretary Peter Hain said arguments between the Prime Minister and Chancellor were inevitable in such high-pressure roles.
But amid claims that Mr Brown had been marginalised in Labour's campaign for the vital local elections in May, he urged behind-the-scenes briefers to "get on with their jobs".
Downing Street angrily dismissed reports that Mr Brown had been axed from Wednesday's main campaign launch and sent instead to a regional event in West Sussex.
In fact Mr Brown had requested the switch so he could be near Gatwick Airport for a trip to the United Nations - which had subsequently been postponed, it was said.
A decision had not yet been taken by the party on whether the Chancellor would appear with the Prime Minister at the main event in London or keep his engagement in Crawley.
May's poll is seen as a test of Mr Blair's popularity in the wake of the "loans for peerages" scandal and rows over school reforms.
Among a flurry of tit-for-tat briefings, the most inflammatory was a suggestion that Mr Brown had deliberately used his Budget to spoil Labour's chances - and speed Mr Blair's exit.
Licensing Minister James Purnell rejected a report that he was behind the story.
"It is preposterous to say that Gordon Brown would do anything other than take the right decisions for the country and Labour's election chances," he said.
There was also a claim that private discussions over the succession had been halted amid recriminations between the two camps. The timing of Mr Blair's departure - he has said he will not lead the party into the next General Election - is causing increasing tension within the party.
Mr Hain said he was not denying that there were tensions and the odd argument, but added that that was "inevitable in any huge operation such as running Government".
He said: "But a lot of the media obsession in this seems in a different world from the one I operate in around the c abinet table and in Government."
Mr Hain - tipped as a possible deputy leader in a Gordon Brown premiership - said he believed the handover of power would be "pretty straightforward".
"People want that and there's an acceptance that he is the most outstanding figure not just in the Labour Party but in British politics at the moment."
Mr Brown would play a "leading role" in the local election campaign, he insisted.
The Sunday Mirror said former Cabinet Minister Alan Milburn was being lined up to challenge the Chancellor for the leadership.
Mr Milburn used a back-bench speech on the Budget last week to launch an attack on the effect of one of the Chancellor's flagship policies on families' tax bills and incentives to get jobs.
Along with a speech on pensions by another former Cabinet Minister, Stephen Byers, it was seen as a coordinated assault by critics dubbed Blairite "outriders".
The latest reports of internal dissent came as a new poll showed that more than half of voters wanted Mr Blair to quit within a year - and that a large majority of them would like to see him go immediately.
Transport Secretary Alistair Darling told the briefers they were "doing absolutely no good either for the people who voted for us last summer or the thousands of Labour Party members who are going to be out on the streets facing tough local elections in May".
Asked if Ministers who briefed should be fired, he added: "I have no time for people who indulge in harmful briefing to the Government and the Labour Party and they shouldn't do it."