Liz Truss has told right-wing Tory MPs her tax U-turns were “painful,” as she continues to try and shore up her support within the party.
The PM told Eurosceptic backbenchers she was still committed to boosting growth through economic reforms, No 10 sources said.
She has been meeting MPs to appeal for support, with her authority undermined after she abandoned flagship tax cuts.
She will appear at PMQs for the first time since the U-turns on Wednesday.
Her performance will be closely watched, particularly after she faced accusations of avoiding MPs on Monday after rejecting a request to explain her U-turns in the Commons.
Some Tory MPs have been talking privately about how she might be ejected from office, despite party rules preventing a formal challenge for a year.
But cabinet ministers have been calling for unity, saying that Ms Truss had been right to jettison her plans to ensure economic stability.
Chancellor Jeremy Hunt tore up most of last month’s mini-budget on Monday, leaving Ms Truss’s economic agenda in tatters after weeks in No 10.
In an attempt to rally support among her MPs, she hosted backbenchers at Downing Street on Tuesday evening and separately met the European Research Group (ERG) of Brexiteer MPs, an influential group on the right of the party.
After the ERG meeting, the prime minister’s deputy press secretary told reporters she had expressed her “disappointment” at “not being able to follow through on the tax cuts”.
“She said she found it painful and that she did it because she had to,” the press secretary added.
Ian Liddell-Grainger, a Tory backbencher who attended the No 10 meeting, said those in attendance were “very blunt about where we feel we are”.
Adding that “a lot of where we’re going is what I want to hear,” he warned colleagues against ejecting Ms Truss, calling it a “recipe for disaster”.
“I think changing horses at this stage would just be ridiculous,” he added.
Ms Truss also told the ERG group she stood by her commitment to increase defence spending to 3% by 2030.
The target – a key plank of her Tory leadership pitch – is a red line for Defence Secretary Ben Wallace, according to his allies.
However, she has not ruled out further tax hikes and spending cuts to provide further reassurance to investors of her commitment to control UK debt.
All government departments have been told to find savings, ahead of a further economic statement by Mr Hunt on 31 October.
Triple lock pledge
Ms Truss has not ruled out raising working-age benefits below inflation to save billions from the social security budget, despite coming under pressure from Tory MPs to guarantee a rise in line with prices.
On Monday, her spokesman also said she was no longer committed to ensuring the state pension keeps pace with inflation, despite making the commitment two weeks ago.
Welsh Secretary Robert Buckland has said: “I think the more the Conservative Party change leaders, the stronger the case for a general election comes.”
Labour wants the Tory party to “chop and change another leader” but an early election “serves nobody any good”, he said, speaking on BBC Newsnight.
“Not least the Conservative Party and certainly not the country.”
Five of the PM’s own MPs have called publicly on her to resign, with others briefing journalists that they think her time in office is up.
Tactics reportedly under consideration to oust her include submitting no-confidence letters in an attempt to force her into resigning.
There has also been speculation some MPs could push party bosses into changing the rules to allow an early leadership challenge.
However, there is little agreement over who should take over from Ms Truss if she is removed.