Foreign Secretary James Cleverly has warned Tory MPs not to sack Liz Truss - as he claimed it could be a nightmare for the economy.
The ally of the crisis-hit PM said any attempt to replace Ms Truss would be a "disastrously bad idea politically and also economically" and said the Government needed to bring certainty to spooked markets.
His desperate plea comes only five weeks into Ms Truss's premiership, which has so far been marred by political chaos and economic turmoil.
Mutinous Conservatives are piling pressure on the PM to abandon her tax-cutting blitz, after a stormy meting of the 1922 Committee of backbenchers where Ms Truss was told she'd "trashed" the Tory record over the past decade.
Mr Cleverly was sent out to defend the Government from mounting criticism - but failed to explicitly rule out further U-turns on her economic plans.
He told BBC Radio 4's Today programme: "We have got to recognise that we do need to bring certainty to the markets.
"I think changing the leadership would be a disastrously bad idea politically and also economically.
"We are absolutely going to stay focused on growing the economy."
It comes after the editor of Tory grassroots bible ConservativeHome website, Paul Goodman, suggested there has been speculation about replacing Ms Truss with a joint ticket of her ex-rivals Rishi Sunak and Penny Mordaunt.
Chancellor Kwasi Kwarteng has flown off to Washington for meetings with the International Monetary Fund as pressure mounts at home for further tweaks to his mini-Budget to ease the economic turmoil.
Mr Cleverly declined to rule out further U-turns but insisted the Government will "absolutely stick" with its tax-cutting principles.
Pressure is mounting on the Chancellor to reinstate a planned corporation tax hike from April in an effort to calm jittery markets.
But Mr Cleverly told Sky News: "I think that it is absolutely right that we want to invest in businesses. It is absolutely right that we help them stay competitive, we help them stay afloat.
"We have got to make sure we can compete internationally with the other places businesses can choose to locate. We have got to make sure we are tax-competitive."
Asked if the Government will stick with the policies of the mini-budget, he said the "bulk" of the mini-budget was the package to protect households and businesses from soaring energy costs.
But it was also "about making sure that taxes for 30 million people were reduced a little bit and those are really strong principles" and "I think we should absolutely stick with those".
He said the planned statement by the Chancellor on October 31 will set out a more "holistic" view of the Government's plans, but the "foundations" of the mini-budget were "really key for the growth agenda the Prime Minister has put forward".
Downing Street declined to say if the PM was worried about a loss of confidence in her leadership after a torrid meeting with backbenchers yesterday.
Asked whether she is worried, her spokesman said: "The Prime Minister's sole focus is on ensuring the delivery of growth through the changes and reforms set out in the growth plan, and obviously on some of the ongoing challenges the war in Ukraine."
