Kemi Badenoch has vowed to “tell the truth” and “stand up for our principles” as she was elected the new leader of the Conservative Party.

The North West Essex MP became the first black woman elected to lead a major UK political party, and the fourth woman to lead the Tories, as she stormed to victory over Robert Jenrick with 56.5% of the vote.

She now replaces Rishi Sunak as leader of the Opposition and will seek to chart a path back to power for the Conservatives after their disastrous defeat at the general election in July.

In her victory speech on Saturday, Ms Badenoch paid tribute to Mr Jenrick and acknowledged that her party had a “huge job” ahead of it, and needed to be “honest” about where it had “made mistakes”.

She said: “The task that stands before us is tough but simple.

“Our first responsibility as His Majesty’s loyal Opposition is to hold this Labour Government to account.

“Our second is no less important. It is to prepare over the course of the next few years for government, to ensure that by the time of the next election, we have not just a clear set of Conservative pledges that appeal to the British people, but a clear plan for how to implement them, a clear plan to change this country by changing the way that government works.”

Ms Badenoch added: “The time has come to tell the truth, to stand up for our principles, to plan for our future, to reset our politics and our thinking, and to give our party, and our country, the new start that they deserve.”

The leaders of Westminster’s main political parties extended their congratulations to Ms Badenoch, with Sir Keir Starmer and Sir Ed Davey both noting that the election of the first black female party leader was a “historic” and “proud” moment for the country.

Mr Sunak also congratulated his successor, urging unity and saying Ms Badenoch would make a “superb” party leader.

Supporters of both Ms Badenoch and Mr Jenrick insisted the party, which has been plagued by division in recent years, would now unite behind its new leader.

Former minister Chris Philp, who endorsed Ms Badenoch, told the PA news agency he was “absolutely certain” the party would now be united, while Jenrick supporter Victoria Atkins said the “Conservative family really wants this to work”.

Ms Badenoch will now begin to choose her shadow cabinet and it is understood that she aims to have her frontbench team appointed ahead of their first meeting due on Tuesday.

The path back to power is a tough one, with just 121 MPs and threats from Labour, the Liberal Democrats and Reform UK.

Commentators suggested the election of Ms Badenoch heralded a right-ward shift for the Conservatives, with a greater focus on so-called “culture war” issues as the party sought to win back voters who opted for Reform in July.

Professor Tim Bale, of Queen Mary University of London, told the BBC this could risk further “alienating” more moderate voters who defected from the Tories to the Liberal Democrats.

He said: “Unless they make a reasonable offer to people on public services, most obviously the NHS, then for all they can talk about boats, bathrooms and boilers, it’s not going to make much difference.”

Polling also suggests a tough challenge for Ms Badenoch, with a YouGov poll published before Saturday’s announcement finding four in 10 voters had a negative view of her, including 29% of people who voted Conservative in July.

Other parties had already begun to attack Ms Badenoch over past comments and positions on Saturday afternoon.

Ellie Reeves, chair of the Labour Party, said she was “quite worried” about comments Ms Badenoch made on maternity pay, autism and the minimum wage while Reform’s Richard Tice said she had been “front and centre of a Government that failed Britain”.