LONDON – Ms Liz Truss said on Thursday she was resigning as prime minister, brought down by her economic programme that sent shockwaves through the markets and divided her Conservative Party just six weeks after she was appointed.

A leadership election will be completed within the next week.

Speaking outside the door of her No. 10 Downing Street office, Ms Truss accepted that she could not deliver the promises she made when she was running for Conservative leader, having lost the faith of her party.

“I recognise though, given the situation, I cannot deliver the mandate on which I was elected by the Conservative Party. I have therefore spoken to His Majesty, the King, to notify him that I am resigning as leader of the Conservative Party,” she said.

“This morning, I met the chairman of the 1922 Committee, Sir Graham Brady. We’ve agreed that there will be a leadership election to be completed within the next week. This will ensure that we remain on a path to deliver our fiscal plans and maintain our country’s economic stability and national security.”

Ms Truss is now the shortest-serving prime minister in British history.

In theory, Ms Truss was protected from a leadership challenge for a year under existing Conservative Party rules. But if enough MPs came out against her, Mr Brady would have been under huge pressure to change the rules to allow a confidence vote.

It is likely that Mr Brady telling Ms Truss she has lost the support of her party prompted her to quit.

Ms Truss’ departure, after only six weeks in office, was a shockingly rapid fall from power, and throws her Conservative Party into further disarray, following the messy departure of Mr Boris Johnson from Downing Street over the summer.

Politically unviable

Ms Truss’ political viability had become tenuous after her proposals for broad unfunded tax cuts roiled markets and sent the pound’s value plunging.

She suffered a grave blow on Monday, when her newly appointed Chancellor of the Exchequer, Mr Jeremy Hunt, said that the government was undoing the last vestiges of Ms Truss’ tax proposals.

That announcement constituted one of the most dramatic reversals in modern British political history, and a humiliating repudiation of Ms Truss’ leadership.

In recent weeks, support for her Conservative Party had collapsed in opinion polls and unrest among its lawmakers intensified, undermining her ability to remain in office.

Mr Hunt also said that the government would end its huge state intervention to cap energy prices in April, replacing it with a still undefined programme that he said would promote energy efficiency, but that could increase uncertainty for households facing rising gas and electricity prices.

Further chaos followed on Wednesday, when Ms Truss was jeered by opposition lawmakers while answering questions in Parliament, and hours later was forced to fire one of her most senior Cabinet ministers, the Home Secretary, Ms Suella Braverman, over a security breach.

Ms Braverman acknowledged having committed a technical breach of security rules, involving a government document that she sent to a lawmaker in Parliament through her personal e-mail.

But in her letter of resignation to Ms Truss, she said she had “concerns about the direction of this government”, accusing it of breaking pledges to voters and, in particular, failing to curb immigration.

On Wednesday, a vote on whether to ban hydraulic fracking erupted into a near melee, with accusations that ministers manhandled Conservative lawmakers and threatened them with retribution if they did not vote to support Ms Truss.

Candidates to replace Ms Truss include former finance minister Rishi Sunak – who warned that her economic policy would damage the economy – or Ms Penny Mordaunt, a minister who is popular with many strands of the party. Mr Hunt is also a strong contender. REUTERS, BLOOMBERG, NYTIMES