Kemi Badenoch rejected a suggestion that the Tories could merge with Reform UK.
The Conservative leader was asked about the two parties teaming up to beat Labour at the next general election after she delivered her first speech of 2025.
She said: “Nigel Farage says he wants to destroy the Conservative Party. Why on earth would we merge with that?”
It comes after senior Tory MP Suella Braverman this week backed the prospect of an election deal with the insurgent party.
Ms Badenoch also addressed Reform catching up with the Tories and even overtaking them in polling.
She said: “Nigel Farage has been knocking around for 20 plus years. He’s been leading all sorts of different parties, so he has had a head start.
“I’ve been leading the Conservative Party for 10 weeks. Let’s see where we are in a few months and years.”
Meanwhile, the Reform leader took a swipe at Mrs Badenoch over the number of people watching her speech live.
The Clacton MP wrote on X: “A total of 21 people are currently watching Kemi Badenoch’s speech on Facebook and her YouTube stream crashed.
“It’s a good job she understands the digital age.”
Mrs Badenoch previously claimed Mr Farage “doesn’t understand the digital age” when the pair became embroiled in a spat over Reform’s membership numbers last month.