LIZ Truss has announced her resignation after just 44 days as Prime Minister.

In a statement in Downing Street, she said she had spoken to King Charles and would remain as Prime Minister until a successor was chosen within a week.

She admitted she was unable to deliver the mandate she came into office to deliver.

She becomes the shortest-serving prime minister in British history.

The pound rose on the back of the announcement.

Opposition parties demanded a general election, saying the Tories cannot have their third Prime Minister this year without the public voting.

Ms Truss emerged from Number 10 after a crisis meeting with Sir Graham Brady, the chair of the 1922 Committee of backbench Tory MPs, who is best placed to know whether a Tory leader has lost the confidence of their parliamentary party.

It came just a day after she insisted in the House of Commons that she would carry on, telling MPs: “I am a fighter and not a quitter."

Accompanied by her husband Hugh O'Leary, she said today: “I came into office at a time of great economic and international instability.

“Families and businesses were worried about how to pay their bills. 

“Vladimir Putin's illegal war in Ukraine threatens the security of our whole continent.

“And our country has been held back for too long by low economic growth. 

“I was elected by the Conservative party with a mandate to change this. 

“We delivered on energy bills along cutting national insurance. 

“And we set out a vision for a low tax high growth that would take advantage of the freedoms of Brexit. 

“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 this morning I met the chairman of the 1922 committee, Sir Graham Brady.

“Wee 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. 

“I will remain as Prime Minister until a successor has been chosen. Thank you.” 

The timing of the contest to find Ms Truss's replacement implies the person will be chosen by a conclave of Tory MPs, as there is too little time to involve the party membership.

Allies of Chancellor Jeremy Hunt said he would not stand for the leadership.

The favourite to take over is former chancellor Rishi Sunak, who lost the summer-long Tory leadership to Ms Truss after being backed by most MPs but rejected by the wider Tory party membership.

His predictions about the market turmoil which would be unleashed by Ms Truss's unfunded tax-cutting plans have proven uncannily accurate.

Ms Truss had been Prime Minister since September 6.

She replaced Boris Johnson, who resigned as Prime Minister in July after a rebellion by his MPs over a series of scandals and byelection losses.

Ms Truss's premiership has been plagued by U-turns on the economy and tax, a loss of authority and a breakdown in party discipline.

She sacked Kwasi Kwarteng as Chancellor last Friday, while Suella Braverman resigned as Home Secretary yesterday with a scathing attack on the PM's record and broken promises.