Pressure is mounting on the prime minister ahead of an emergency statement by her new chancellor Jeremy Hunt to reassure financial markets over the government's economic plans, BBC reports.
Mr Hunt is expected to U-turn on more of the government's tax-cutting plans.
He is also expected to provide more clarity on public sector spending - two weeks earlier than planned.
Three Tory MPs have said Liz Truss must go as prime minister, a message echoed privately by many Conservative MPs.
Mr Hunt is set to make an announcement on the government's plans by lunchtime, followed by a statement in the House of Commons in the afternoon.
The cut to National Insurance is expected to survive as it is already close to passing through Parliament.
However, there could be changes to plans to cut the basic rate of income tax from 20p to 19p.
Financial markets appeared to welcome the prospect of more changes to the government's economic plans.
On Friday, Ms Truss sacked her Chancellor Kwasi Kwarteng and abandoned one of her flagship policies to freeze corporation tax, in response to market turmoil and opposition for her own MPs.
Three Tory MPs - Crispin Blunt, Andrew Bridgen and Jamie Wallis - have since gone public calling for the prime minister to go.
Many others are expressing concerns privately.
"It's done... we can't win," one minister, a Truss supporter who was accepting they will lose their seat whenever a general election comes, told the BBC.
Senior Conservative Mr Blunt, who supported Ms Truss's rival Rishi Sunak in the last leadership election, told the BBC the prime minister's position was "untenable".
He said the appointment of Mr Hunt had "begun to repair some of the damage" but a change of prime minister was needed as well.
In conversations with the BBC over the weekend, many other Conservatives argued Ms Truss would have to leave office before the next election.
Some believed she could hang on for a few months but an increasing number argued she has weeks or even days left.
Under current Conservative Party rules, Ms Truss is safe from a no confidence vote by Tory MPs to oust her for a year. The rules could be changed, however sources suggested to the BBC that the 1922 committee of backbench MPs, who set the rules, would prefer the prime minister to jump before she is pushed.
Some Tory MPs who want Ms Truss to go have suggested putting forward just one candidate to replace her, with MPs choosing their next leader in a couple of days without consulting members, as would normally happen.
The three names being widely discussed are Defence Secretary Ben Wallace, Commons leader Penny Mordaunt and former Chancellor Mr Sunak.
However, there is little agreement over who should take over from Ms Truss if she is removed.
