Susan Hall has been selected as the Conservative Party’s candidate in next year's London mayoral election to face Labour's Sadiq Khan.
The London Assembly member promised to tear up Mr Khan's planned expansion of the Ulez (ultra-low emission zone) on her first day, if elected.
She defeated Mozammel Hossain, a criminal barrister, with 57 per cent of the vote from London Tory members.
“It is a huge honour to be the Conservative candidate for Mayor of London, I’m so grateful to everyone for their support," she wrote on Twitter.
Ms Hall vowed to "work tirelessly to defeat Sadiq Khan and offer Londoners the change we need".
She has been a London Assembly member since 2017, is a Harrow councillor and ran under the slogan Safer with Susan.
The mayoral hopeful has accused Mr Khan of wasting public money, failing to tackle crime and having no “interest in loving others”.
She also said he has not made any significant achievements during his time in office.
“He goes on trips while young people get stabbed on our streets,” Ms Hall said.
“He’s more interested in selling his book than he is helping Londoners with the cost of living.
“When things go wrong, he hires an army of spin doctors to convince you it’s actually not his fault.
“I’ll do whatever it takes to win.”
She added that in the next 10 months she will expose Mr Khan for “who he truly is”.
She thanked rival Mr Hossain for his “positive and hard-fought campaign”.
The election is scheduled to take place on May 4 next year.
Mr Khan was reselected as Labour's candidate in a contest in December and is vying for a historic third term in City Hall.
Mr Khan responded to the announcement by saying: "The Tories have failed the country. We can’t let them fail London, too."
Ms Hall’s views on a host of issues were put to Prime Minister Rishi Sunak’s team on Wednesday.
Asked if Mr Sunak shared the mayoral hopeful's view that Liz Truss’s mini-budget was a moment of “joy” for the UK, his spokeswoman suggested he did not.
Ms Hall’s decision to back Home Secretary Suella Braverman's comments that the UK was experiencing an “invasion” of illegal migrants was also raised. Mr Sunak “would not characterise [the Channel crisis] in those terms”, his spokeswoman said.
Ms Hall’s comparison between Donald Trump supporters who stormed the Capitol on January 6, 2021, with anti-Brexit politicians in the UK was also touched on. Mr Sunak’s spokeswoman said he would not characterise the two groups in the same way.
Asked if Mr Sunak considers Ms Hall a liability to the Conservative Party, No 10 said: “No. She has shown great commitment to bettering London with the Conservatives and highlighting the many failures of Sadiq Khan including his desire to charge people up to £12.50 a day, as the Prime Minister said, just to visit their GP.
"She has the full support of the PM.”
London Labour branded Ms Hall "extreme".
“The Conservative candidate for mayor is a hard-right politician who couldn’t be more out of touch with our city and its values,” a representative for London Labour said. “She’s an outspoken supporter of [Donald] Trump, Boris Johnson and a hard Brexit; she cheered Liz Truss’s mini-budget, which sent mortgages and rents soaring.
“She doesn’t stand up for women and she hates London’s diversity.
“Londoners deserve better than a candidate who represents the worst of the Tory failure and incompetence over the last 13 years.
"The London election next year will be a two-horse race and the choice is clear – a Labour mayor with a positive vision who will continue to build a fairer, greener and safer London for everyone, or the extreme Tory candidate, who stands for cuts to London’s public services, inequality and division.”
Caroline Pidgeon, Liberal Democrat London Assembly member, accused the Conservatives of having "given up on London". She said the party was pushing a "brand of populism and social conservatism" on the capital that "doesn’t resonate with most Londoners".
David Cameron's former special adviser Daniel Korski dropped out of the Tory mayoral candidacy race after allegations of inappropriate behaviour were made against him.