Gordon Brown was tonight facing calls to spare Chancellor Alistair Darling as he prepared to reshuffle the Cabinet to shore up his tottering premiership.
Supporters of Mr Darling insisted there was no mood on the Labour backbenches for a change at the Treasury and they warned against a humiliating demotion for the Chancellor.
The Prime Minister is widely thought to want to install his old ally Children's Secretary Ed Balls in the Treasury in his shake up of his ministerial pack which could come as early as tomorrow.
However his calculations have been complicated by Mr Darling's reported refusal to accept a move to the Home Office.
Mr Brown is well aware that Mr Darling could trigger a run of other ministerial resignations if he was to walk away from the Cabinet - with potentially devastating consequences for his chances of survival at No 10.
Equally, failure to impose his will and move Mr Darling could be seen as a fatal sign of weakness at a time when plotters on the Labour backbenches are thought to be preparing to move against him.
With David Miliband also resisting any attempt to move him from the Foreign Office, the stakes for Mr Brown could not be higher.
The calls to keep Mr Darling as Chancellor were led by Labour Party vice chairman Stephen Ladyman who insisted that there was no justification for replacing him.
"He has done a fine job as Chancellor," he told BBC Radio 4's The World at One.
"He took on a crisis that nobody could see coming. It wasn't of his making or the Government's making. He has dealt with it extremely well, he has led the world out of this crisis, so frankly I don't see any reason for moving him.
"Certainly, I don't think there is anybody who thinks he deserves to be demoted or humiliated in any way. He has done an excellent job."
Labour backbencher Eric Joyce said that Mr Darling should stay on to deal with the economic crisis.
"He has been a really first class Chancellor. At the moment we are facing the biggest economic crisis we have known for years. Gordon and Alistair seem to be the best placed to deal with it," he said.
Mr Brown spent the day working in Downing Street where his mood was said to be "determined".
"The Prime Minister is focused on getting the job done on renewing trust in our political system and our democratic processes and taking the kind of decisions that will help the British people get through difficult economic circumstances," a No 10 spokesman said.
After yesterday's high drama - which saw the resignation of Communities Secretary Hazel Blears in direct challenge to Mr Brown's authority - Westminster was unusually quiet as voters went to polls in the European and local council elections.
Backbench plotters who were preparing to circulate a round-robin email to Labour MPs calling on Mr Brown to stand down appeared to be lying low until the polls close at 10pm tonight.
Labour is braced for a mauling - although with most councils not counting until tomorrow and the European election results not due until Sunday evening - it will be the end of the weekend before the full damage becomes clear.
It is thought the rebels - who were said to be hoping to get the support of at least 80 MPs signatures - will release their list of backers at some stage over the coming days in a bid to force Mr Brown's hand.
All the signs were however that he was determined to fight back against any attempt to remove him.