Rishi Sunak-backers say "dissatisfaction is so high", however, making place for another PM in quick succession is not something the party can afford.

One former minister told the BBC: "We cannot go on like this indefinitely". 
However, several of Boris Johnson's supporters would do anything to stop Indian-origin Sunak from taking over.

Another Tory MP said the party was in a "state of despair" after the PM's Downing Street news conference.

Truss supporter Christopher Chope said "time will tell" if she had done enough to secure her position but those plotting to remove her were "hyenas".

Sir Christopher said: "We can't possibly force another prime minister out of office, we've just got to calm down and try to give the prime minister our support."

On Friday, Truss sacked her chancellor, Kwasi Kwarteng, and reversed a key policy to scrap the planned rise in corporation tax from 19 to 25 per cent. The statement marks the second major U-turn on the mini-budget after Truss cancelled her plan to scrap the top rate of income tax earlier this month.

The U-turn on corporation tax is "going to be damaging to the prospects for growth" and is "totally inconsistent" with what she said during the campaign, Sir Christopher said.

Conservative MP for Coalville, Andrew Bridgen, said he thinks "there'll be a challenge to Truss in the next few weeks".

Bridgen, who backed Rishi Sunak to be leader, said: "Dissatisfaction is so high in the parliamentary party.

"Removing Kwasi Kwarteng when he implemented the policies she asked him to do won't engender loyalty to her."

On September 23, Kwarteng unveiled a so-called mini-budget to deliver the prime minister's vision, announcing the biggest package of tax cuts in decades. But the mini-budget spooked financial markets and sparked a revolt among Tory MPs, who urged the prime minister to drop parts of her economic plan to shore up the UK's finances.

Privately many Conservative MPs admit they have gone through despondency and into despair over the past 24 hours, the BBC said.

By going back on her promise to cut taxes she has now alienated some of those who backed her in the leadership contest for her "bold" approach.

It is not hard to find Tory MPs who think her time is up.

One former backer told the BBC, Truss had "appointed her successor," by bringing in Jeremy Hunt as chancellor. "Sadly I think that hastened her demise," the Conservative MP said.

Another MP called Truss's news conference "a mega-disaster". They said: "She will have to resign - she is worse than Corbyn."

Truss insisted she would stay on as prime minister to see through her "mission" to get the economy growing.

"I'm absolutely determined to see through what I promised - to deliver a higher growth, more prosperous United Kingdom to see us through the storm we face," Truss said.

The eight-minute news conference came after a dramatic day in which the prime minister fired Kwarteng after he returned early from a US summit.

Members of Truss's cabinet are not in open revolt. Many allies have been tweeting support for her and the new chancellor, Hunt.

Former chancellor Nadhim Zahawi tweeted: "It's time to get Britain moving. We are determined to grow the economy, eliminate the Covid backlog and protect people from Putin's energy warfare."

In a tweet, Deputy Prime Minister Therese Coffey - a close ally of Truss - said the prime minister was "right to act now to ensure our country's economic stability".

And Business and Energy Secretary Jacob Rees-Mogg tweeted: "As a government, we must now get on and deliver the pro-growth reforms that will lay the foundations for our future prosperity."

The Liberal Democrats and the SNP have called for a general election, while shadow chancellor Rachel Reeves said a new government led by Labour is "what this country needs".

Truss has ruled out a general election until 2024.

Many in the parliamentary Conservative party think they have to avoid another drawn-out leadership contest where Tory members have the final say.

The idea cropping up most is a joint ticket with former chancellor Rishi Sunak and Penny Mordaunt. But after 12 years in power, under four different leaders, there are many old scores to settle in the Tory Party, the BBC said.

(With UNI inputs)