Andrea Leadsom has sensationally withdrawn from the race to be leader of the Conservative party, leaving Theresa May as the sole candidate to succeed David Cameron as prime minister.
In an unexpected move, the energy minister – who won the backing of 84 Tory MPs in a ballot only last week – said she did not believe she could command the confidence of the parliamentary party, and confirmed that she would step aside to make way for May.
In a letter to Graham Brady, chairman of the powerful 1922 committee of backbench Conservative MPs, the strongly pro-Brexit Leadsom said the referendum on Britain's membership of the European Union had shown "a clear desire for change", but said strong leadership was now needed "urgently to begin the work of withdrawing from the European Union".
Andrea Leadsom and Theresa May to go head-to-head in race to be new prime minister
"A nine-week leadership campaign at such a critical moment for our country is highly undesirable," she added.
"Business needs certainty. Strong and unified government must move quickly to set out what an independent United Kingdom's framework for business looks like. It is also essential that current EU workers in the UK and businesses that employ them know where they stand."
Leadsom said the UK needed a prime minister in place "as soon as possible", and said she had concluded that home secretary May's strong support in the parliamentary party – with 199 MPs backing her – meant the home secretary was "ideally placed to implement Brexit on the best possible terms for the British people".
"For me personally to have won the support of 84 of my colleagues last Thursday was a great expression of confidence for which I am incredibly grateful," Leadsom said.
"Nevertheless this is less than 25% of the parliamentary party. And after careful consideration I do not believe this is sufficient support to lead a strong and stable government should I win the leadership election.
The energy minister added: "There is no greater privilege than to lead the Conservative party in government and I would have been deeply honoured to do it.
"I have however concluded that the interests of our country are best served by the immediate appointment of a strong and well-supported prime minister. I am therefore withdrawing from the leadership election and I wish Theresa May the very greatest success. I assure her of my full support."
Leadsom's move, which follows a weekend of controversy over remarks she made about motherhood in a Times interview, leaves the original timeframe for Cameron's departure in tatters, and raises the prospect of May becoming prime minister by the end of the week.
A new Tory leader had originally been expected to be in place by early September. But immediately after Leadsom's statement Brady, the 1922 chair, said he would now seek to "formally confirm" with the party's board that May had become Tory leader – and ruled out reopening the contest.
Pressed for a timeframe on when May would become prime minister, Brady told reporters: "It won't be nine weeks: I can be very clear about that."
He promised a further statement later on Monday.