UK Prime Minister Liz Truss was hanging on to power by a thread on Thursday, after a senior minister quit her government with a barrage of criticism and a vote in the House of Commons descended into chaos and acrimony.

A botched economic plan unveiled by the government last month triggered financial turmoil and a political crisis that has seen the replacement of Truss' Treasury chief, multiple policy U-turns and a breakdown of discipline in the governing Conservative Party.

Many Conservatives say Truss must resign - but she has remained defiant, saying she is "a fighter and not a quitter."

Conservative lawmaker Simon Hoare said the government was in disarray.

"Nobody has a route plan. It's all sort of hand-to-hand fighting on a day-to-day basis," he told the BBC on Thursday. He said Truss had "about 12 hours" to turn the situation around.

Newspapers that usually support the Conservatives were vitriolic. An editorial in the Daily Mail was headlined: "The wheels have come off the Tory clown car."

International Trade Secretary Anne-Marie Trevelyan, sent onto the airwaves Thursday morning to defend the government, insisted the administration was providing "stability." But she was unable to guarantee Truss would lead the party into the next election.

"At the moment, I think that's the case," she said.

With opinion polls giving the Labour Party a large and growing lead, many Conservatives now believe their only hope of avoiding electoral oblivion is to replace Truss. But they are divided about how to get rid of her and as yet there is no front-runner to succeed her.

A national election does not have to be held until 2024, and under Conservative Party rules, Truss technically is safe from a leadership challenge for a year. The rules can be changed if enough lawmakers want it. There is fevered speculation about how many lawmakers have already submitted letters calling for a no-confidence vote.

In a major blow, Home Secretary Suella Braverman resigned Wednesday after breaching rules by sending an official document from her personal email account. She used her resignation letter to lambaste Truss, saying she had "concerns about the direction of this government."

"The business of government relies upon people accepting responsibility for their mistakes," she said in a thinly veiled dig at Truss.

Braverman was replaced as home secretary, the minister responsible for immigration and law and order, by former Cabinet minister Grant Shapps. He's a high-profile supporter of Rishi Sunak, the former Treasury chief defeated by Truss in the final round of the Conservative leadership race.

Truss faced more turmoil in Parliament Wednesday evening on a vote over fracking for shale gas - a practice that Truss wants to resume despite opposition from many Conservatives.

With a large Conservative majority in Parliament, an opposition call for a fracking ban was easily defeated, but some lawmakers were furious that Conservative Party whips said the vote would be treated as a confidence motion, meaning the government would fall if the motion passed.

There were angry scenes in the House of Commons, with party whips accused of using heavy-handed tactics to gain votes. Labour lawmaker Chris Bryant said he "saw members being physically manhandled ... and being bullied." Conservative officials denied there had been manhandling.

Rumors swirled that Conservative Chief Whip Wendy Morton, who is responsible for party discipline, and her deputy had resigned. Hours later, Truss' office said both remained in their jobs.

The dramatic developments came days after Truss fired her Treasury chief, Kwasi Kwarteng, on Friday after the economic package the pair unveiled Sept. 23 spooked financial markets and triggered an economic and political crisis.

The plan's 45 billion pounds (50 billion) in unfunded tax cuts sparked turmoil on financial markets, hammering the value of the pound and increasing the cost of U.K. government borrowing. The Bank of England was forced to intervene to prevent the crisis from spreading to the wider economy and putting pension funds at risk.

On Monday Kwarteng's replacement, Treasury chief Jeremy Hunt, scrapped almost all of Truss' tax cuts, along with her flagship energy policy and her promise of no public spending cuts. He said the government will need to save billions of pounds and there are "many difficult decisions" to be made before he sets out a medium-term fiscal plan on Oct. 31.

Speaking to lawmakers for the first time since the U-turn, Truss apologized Wednesday and admitted she had made mistakes during her six weeks in office, but insisted that by changing course she had "taken responsibility and made the right decisions in the interest of the country's economic stability."

Opposition lawmakers shouted "Resign!" as she spoke in the House of Commons.

But she insisted: "I am a fighter and not a quitter."