Tony Blair has praised Gordon Brown's record as chancellor but refused to be drawn on whether he will have a job if Labour is re-elected for a third term.
The prime minister held his monthly press conference on Thursday
The prime minister was speaking during his monthly news conference.
Simultaneously the chancellor was delivering his long-planned speech on the UK's plans to tackle global poverty with a "new Marshall Plan" for Africa.
Mr Blair played down new rumours of a rift, stressing shared agendas over the developing world and domestic issues.
The timing of Mr Blair's media conference - announced on Wednesday - was seen by some of Mr Brown's allies as a deliberate snub because it clashed with the long arranged speech by the chancellor.
Mr Brown, asked about it by the BBC on Thursday, said the timetabling clash was a coincidence and showed the two men had a shared agenda.
But the chancellor's former spin doctor Charlie Whelan said the timing of the press conference was "astonishing".
Ex-chairman of the Parliamentary Labour Party Clive Soley agreed there were disagreements between Mr Brown and Mr Blair.
"There are, and there are sometimes some pretty impressive rows. Nobody has any doubts about that," he told BBC Radio 4's World at One.
But Foreign Secretary Jack Straw branded the latest controversy over the timing of Mr Blair's news conference and Mr Brown's speech as "wholly synthetic".
Hundreds of millions
Lib Dem president Simon Hughes said: "The last thing the people of South-East Asia and Africa need is a New Year pantomime where the two leading men are trying to outplay each other for the starring role."
And Tory international development spokesman Alan Duncan accused the premier and chancellor of "squabbling like children in the playground".
He announced a Conservative Government would increase the DFID budget from £4.5bn in 2005/6 to £5bn in 2006/7 and then £5.3 in 2007/8 - matching Labour's commitment.
At the news conference Mr Blair said he did not want to get into a "game I cannot win" of either assuming victory at the next election or of naming his next cabinet.
"I'm not getting into the business of what happens after elections and reshuffles and all the rest of it," he added.
"But I can tell you, he's done a superb job for many years and I have no doubt he will continue to do a superb job."
Mr Blair predicted the government would eventually give "hundreds of millions" of pounds in aid to countries hit by the tsunami. The public have donated £76m to date.
So far 41Britons are known to have died in the tragedy with 158 still unaccounted for.
The prime minister returned from holiday in Egypt this week and in an interview on Wednesday insisted that he had been "intimately involved" in "all decisions at all times" relating to UK reaction to the tsunami tragedy despite being abroad.
He contrasted the natural disaster in Asia with the "man made" situation with Africa saying there was the equivalent of the tsunami in that continent every week.
"I do not accept there is compassion fatigue on behalf of the British people," he said hailing the UK public's donations.
"On the contrary, I believe there is every chance of mobilising the same
extraordinary generosity of spirit and solidarity that Britain and the world
have shown over the tsunami tragedy in supporting the tackling of the tragedy in
Mr Brown's hopes of a new Marshall Plan for Africa, is an attempt to recreate the huge investment made by the US in rebuilding post-war Europe.