New U.K. finance minister Jeremy Hunt sought to rebuild investor confidence in Britain Monday by reversing nearly all of Prime Minister Liz Truss's mini-budget that had sparked market turmoil, and reining in a vast energy subsidy plan.

Tasked with halting a bond market rout that has raged since the government announced huge unfunded tax cuts on Sept. 23, Hunt said the country now needed to increase taxes and cut spending to rebuild stability and confidence.

The former health and foreign minister has now reversed nearly all of the program that helped to Truss win the leadership of the ruling Conservative Party just over a month ago, leaving the prime minister fighting for her future.

A two-year energy support scheme for households and businesses, expected to cost more than 100 billion pounds, will now end in April and be replaced by a more targeted scheme that will "cost the taxpayer significantly less than planned."

The pound soared by as much as 1.4% to a session high of $1.1332, after the statement. It was last up just under 1% broadly where it was just before the announcement.

British government bonds rallied aggressively on Hunt's statement and looked on course for one of their biggest daily price increases since records began.

"We will reverse almost all the tax measures announced in the Growth Plan three weeks ago that had not started parliamentary legislation," Hunt said.

He said changes to planned tax cuts would raise 32 billion pounds ($36 billion) every year.

"I remain extremely confident about the UK's long term economic prospects as we deliver our mission to go for growth," Hunt said in a televised clip. "But growth requires confidence and stability, and the United Kingdom will always pay its way."

The government has been forced to reverse course after markets reacted violently to Truss's plan, hammering the value of the pound and government bond prices and forcing the Bank of England to intervene to protect pension funds.

Adding to the pressure, the Bank stuck to its schedule of ending the support on Friday, meaning Hunt had been racing to reverse policies and find spending cuts to appease the markets and prevent borrowing costs from rising further on Monday morning.

He said government spending cuts would be required to narrow a hole in public finances that the Sunday Times reported was as big as 72 billion pounds ($81 billion).

The near total reversal of the economic plan leaves Truss struggling to retain credibility. Her about-turn has angered those lawmakers who supported her, and further encouraged those who opposed her to try to find a way of getting her out of power.

The fourth British prime minister in six years, she was only formerly appointed to the role on Sept. 6.

Already a handful of her lawmakers have said she must go. Rachel Reeves, the finance spokesperson for the opposition Labour Party, said the Conservative government was no longer capable of providing stability.

"The Conservatives have lost all credibility," she said.

While Hunt had been expected to reverse some of the tax cuts, the change to the energy support scheme came out of the blue.

Truss had announced a two-year subsidy scheme to support households and businesses through the period of surging energy prices, which would cost 60 billion pounds in six months alone. Hunt said on Monday that the scheme would now run until April, but become more targeted after that.

The new finance minister would still deliver a fuller medium-term fiscal plan as scheduled on Oct. 31, alongside forecasts from the independent Office for Budget Responsibility, the Treasury said. ($1 = 0.8887 pounds)