Kemi Badenoch has promised to “renew” the Conservatives after being elected party leader, defeating fellow right winger Robert Jenrick.
She takes over from Rishi Sunak, who led the Conservatives to their worst ever election defeat in July.
In her victory speech, she told party members it is “time to get down to business” and “time to renew”.
Badenoch, who was raised in Nigeria, is the first black woman to lead a major political party in the UK.
She is the sixth Tory leader in less than eight and a half years and faces the challenge of uniting a fractured party.
Her “first responsibility” as the new Tory leader “is to hold this Labour government to account,” she said.
“Our second is no less important – it is to prepare over the course of the next few years for government.”
Badenoch said the party needed to focus on plans to “bring back” voters who abandoned the Conservatives, adding: “Our party is critical to the success of our country.
“But to be heard, we have to be honest.”
The party must admit it “made mistakes” and “let standards slip” over the last 14 years in government, she said.
In her speech she hinted at a senior job for Jenrick, telling him “you have a key role in our party for years to come.”
The final result saw Badenoch win with 53,806 votes compared to Jenrick’s 41,388 votes – the closest leadership vote in the party’s history.
Bob Blackman, who oversaw the election as chair of the Conservative 1922 Committee, revealed the party membership had shrunk to just under 132,000 – down from 172,000 in 2022.
All eyes will now turn to who Badenoch appoints to her top team as she sets out the future shape of the party.
The BBC has been told Badenoch is not planning to announce the members of her to shadow cabinet on Saturday.
Badenoch previously said she would offer a frontbench job to all six of her rivals in the leadership race.
But shadow home secretary James Cleverly, who came third in the race, and shadow environment secretary Steve Barclay have already ruled themselves out of a frontbench role.
She was congratulated by her predecessor Sunak, who posted on social media: “I know that she will be a superb leader of our great party.
“She will renew our party, stand up for Conservative values, and take the fight to Labour.”
Ex-prime minister Boris Johnson lauded Badenoch’s “courage and clarity” and said she “brings a much needed zing and zap to the Conservative Party”.
“Kemi has exactly the right courage and clarity to expose Starmer’s failings,” he said.
In a social media post, Prime Minister Sir Keir Starmer said “the first Black leader of a Westminster party is a proud moment for our country”.
“I look forward to working with you and your party in the interests of the British people,” he said.
But Labour Party Chair Ellie Reeves said the Conservative leadership campaign showed the party had “learned nothing since the British people resoundingly rejected them in July”.
She said: “They could have spent the past four months listening to the public, taking responsibility for the mess they made and changing their party.
The party suffered its worst general defeat in its history in July as it was reduced to a record low of 121 seats in the House of Commons, with under 24% of the vote.
The party lost voters in all directions to Labour, the Liberal Democrats and Reform UK, with thousands of Conservative voters also choosing to stay at home on 4 July poll.
Dame Priti Patel, Mel Stride and Tom Tugendhat spent the summer campaigning alongside Jenrick, Badenoch and Cleverly after they put their names forward in the nominations at the end of July.
Dame Priti and Stride were the first two contenders to be eliminated in September in ballots of Tory MPs, leaving four by the time the party gathered in Birmingham for its autumn conference at the end of the month.
Source: BBC
