LONDON - Britain's beleaguered Prime Minister Liz Truss is battling to rescue her premiership this week, when financial markets will deliver a fresh verdict on her screeching economic reset while mutinous backbenchers plot to oust her.

Only 40 days in office, Ms Truss spent Sunday huddling with new Chancellor of the Exchequer Jeremy Hunt, her pick to restore stability after a humiliating climbdown that included sacking her initial choice for the job and junking an economic plan that triggered a sell-off in British assets.

While markets will be testing Ms Truss, her fate ultimately rests with a Conservative Party that has her scrambling to save her job.

She will host a reception for the Cabinet at No. 10 Downing Street on Monday evening to continue to get their input into a medium-term fiscal plan, which Mr Hunt will announce on Oct 31, according to an official familiar with the matter.

Mr Hunt will also host meetings with all Conservative MPs this week to get their feedback, the official said.

Mr Hunt spent the weekend outlining a radically different fiscal approach - taxes would have to rise, spending would have to be cut - in a bid to prevent further punishing increases in British government borrowing costs.

Gilts sold off dramatically last Friday afternoon after an underwhelming press conference by Ms Truss, and the Bank of England's emergency bond-buying programme, introduced to calm markets after Ms Truss unveiled her mini-budget, has now expired.

The pound rose in early Asian trading on Monday as investors speculated that more of her package of unfunded tax cuts might be reversed.

If Ms Truss can weather the markets, her second test will be to grapple with a party in open revolt.

As of Sunday evening, three Tory MPs were publicly calling for her to quit and multiple others said privately that they will write to Mr Graham Brady, the chairman of the backbench 1922 Committee, urging him to change party rules so a vote of confidence can be held.

More than 100 British lawmakers will try to oust Ms Truss this week despite Downing Street's warning that it could trigger a general election, the Daily Mail reported, with the MPs prepared to submit letters of no confidence in her.

The MPs will urge Mr Brady to tell Ms Truss that “her time is up” or to change the political party rules to allow an immediate vote of confidence in her leadership, the report said.

Plotting against Ms Truss is accelerating because the Tories are spooked by a record poll deficit against Labour and the belief they face electoral meltdown if she is allowed to stay in post.

Supporters of Mr Rishi Sunak, who came second to Ms Truss in the recent Tory leadership contest, stepped up efforts over the weekend to secure support to install him.

Mr Julian Smith, a former chief whip, has been in touch with multiple Conservative MPs to gauge support for a so-called Sunak coronation, bypassing another vote from the party's grassroots supporters. Mr Mel Stride, a vocal critic of Ms Truss and a Sunak supporter, is hosting a dinner for MPs on Monday evening, following a similar event last week.

An ally of Ms Truss warned that the plotters do not have any regard for Britain's economic prosperity or the fate of the markets. The plotters will not get a coronation and will simply bring about a general election, the person said.

Ms Truss' position is protected by a one-year immunity clause under current Conservative rules. About two-thirds of the party's nearly 360 MPs need to tell the 1922's executive to change the rules before it would do so, according to a person familiar with its deliberations, meaning an imminent ouster of Ms Truss is not likely. The executive will not meet until Wednesday, the person said.

Still, Ms Truss could plausibly limp on for weeks or months with the markets calmed, her policy platform reversed and Mr Hunt effectively in charge, according to a senior Conservative operator who spoke on condition of anonymity. This is the most likely outcome, the person said, because there is no unity candidate and enough MPs want to give the new Hunt operation a chance.

Fighting to keep her premiership alive, Ms Truss spent Sunday locked in talks with her chancellor at her official country residence about the contents of the government's medium-term fiscal plan.

Earlier, Mr Hunt said nothing is "off the table" when asked whether he will abandon more of Ms Truss' tax-cutting agenda, confirming that his is now the leading government voice on British fiscal policy.

In a BBC interview on Sunday, Mr Hunt declined to rule out delaying by a year the Prime Minister's plan to cut the basic rate of income tax, a move that would amount to another U-turn. A delay could save £5 billion (S$8 billion), according to a report in the Sunday Times.

But it is still a live question about whether Ms Truss even survives until Halloween for the fiscal plan, with her fate resting in the hands of financial markets and her backbenchers.

Ms Truss has "undermined Britain's credibility as a trustworthy, responsible leading economy, and fractured our party in a potentially irreparable manner", Tory MP Jamie Wallis said in his letter calling for her resignation. "You no longer hold the confidence of the country or the parliamentary party." BLOOMBERG