Liz Truss has stepped down as prime minister.
The South West Norfolk MP made the announcement on the steps of Downing Street after meeting with Sir Graham Brady, the chairman of the 1922 Committee of backbench MPs, which oversees the election of Conservative leaders.
It is understood that Ms Truss requested the meeting with Sir Graham.
Her resignation makes her the shortest serving prime minister in British history. She has been in Downing Street for 44 days.
In her statement, she said: “I came into office at a time of great economic and international instability.
"Families and businesses were worried about how to pay their bills.
"Putin’s illegal war in Ukraine threatens the security of our whole continent.
"And our country had 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 and on cutting national insurance.
"And we set out a vision for a low tax, high growth economy – 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."
It comes after Prime Minister’s Questions on Wednesday, October 19, where Ms Truss insisted, “I am a fighter, not a quitter”.
But things unravelled in dramatic fashion after that, with Suella Braverman resigning as home secretary over a breach of ministerial rules relating to sending an official document from her personal email.
Her resignation letter suggested the real reason for her departure was a blazing row with Ms Truss over immigration policy, raising “serious concerns” about the government and its “commitment to honouring manifesto commitments, such as reducing overall migration numbers”.
Later on there was further turmoil in the party over a vote on fracking.
And now, after a little more than six weeks, upheaval, resignations and embarrassing U-turns she has quit Number 10.
Keir Starmer MP, Leader of the Labour Party, responding to Liz Truss’ resignation, said: “The Conservative Party has shown it no longer has a mandate to govern.
“After 12 years of Tory failure, the British people deserve so much better than this revolving door of chaos. In the last few years, the Tories have set record-high taxation, trashed our institutions and created a cost-of-living crisis.
"Now, they have crashed the economy so badly that people are facing £500 a month extra on their mortgages. The damage they have done will take years to fix.
“Each one of these crises was made in Downing Street but paid for by the British public. Each one has left our country weaker and worse off.
“The Tories cannot respond to their latest shambles by yet again simply clicking their fingers and shuffling the people at the top without the consent of the British people. They do not have a mandate to put the country through yet another experiment; Britain is not their personal fiefdom to run how they wish.
“The British public deserve a proper say on the country's future. They must have the chance to compare the Tories’ chaos with Labour’s plans to sort out their mess, grow the economy for working people and rebuild the country for a fairer, greener future. We must have a chance at a fresh start. We need a general election - now.”
Liz Truss said there would be a leadership election to replace her “to be delivered within the next week”.
In her statement, she added: "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 plan and maintain our country’s economic stability and national security.
“I will remain as prime minister until a successor has been chosen."
Ms Truss was originally elected as Conservative Party leader on September 5 and took over as prime minister the following day.
Her premiership had barely begun when politics ground to a halt following the death of the Queen.
The pivotal event of her time in office was then-chancellor Kwasi Kwarteng’s mini-budget on September 23, which triggered turmoil in the financial markets and required an emergency intervention by the Bank of England to support government bonds.
Mr Kwarteng was sacked and replaced by Jeremy Hunt, who junked almost all of the tax cuts which had been a key part of Ms Truss’ appeal to party members.
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