Liz Truss has won the contest to become the new prime minister beating her rival Rishi Sunak.
In her victory speech she pledged to “deliver, deliver, deliver” in Downing Street.
She promised that she would “deliver on the energy crisis, dealing with people’s energy bills but also dealing with the long-term issues we have on energy supply’” as well as on the challenges facing the NHS.
And she hinted at ruling out an early general election, saying she would deliver “a great victory” for her party in 2024.
Ms Truss secured the backing of more than 81,000 party members to become the new leader of the Conservative Party, by a margin of 57 to 43 per cent.
She will be the fourth Conservative prime minister since 2016, when David Cameron quit after losing the Brexit vote. But she will not be asked to form a government until tomorrow, when she visits the Queen at Balmoral.
Ms Truss was widely expected to win after polls suggested she was the frontrunner in the contest to replace Boris Johnson.
In her speech she thanked Tory voters “for putting your faith in me to lead our great Conservative Party, the greatest political party on earth.
“I know that our beliefs resonate with the British people: our beliefs in freedom, in the ability to control your own life, in low taxes, in personal responsibility.
“I know that’s why people voted for us in such numbers in 2019 and as your party leader I intend to deliver what we promised those voters right across our great country.”
She added: “We all will deliver for our country and I will make sure that we use all the fantastic talents of the Conservative Party, our brilliant Members of Parliament and peers, our fantastic councillors, our MSs, our MSPs, all of our councillors and activists and members right across our country.
“Because my friends, I know that we will deliver, we will deliver and we will deliver. And we will deliver a great victory for the Conservative Party in 2024.”
An announcement on help with household energy bills will be made within days, she has pledged. She is thought to be considering freezing them in some form in a bid to ease the burden on millions this winter.
But she has also warned that there will be difficult decisions ahead as the government grapples with an escalating cost of living crisis. Not all of those decisions will be popular, she has said.
She has also defended her plans to cut taxes, even when the move would help high earners significantly more than the less well off. She has insisted that such a cut would be “fair” because top earners pay more tax overall.
Ms Truss argues that cutting taxes will raise revenue in the long term, in part because it will encourage more businesses to invest in the UK. “To look at everything through the lens of redistribution, I believe, is wrong,” she said on Sunday. “Because what I’m about is about growing the economy and growing the economy benefits everybody.”
More follows…