Britain was searching for a new prime minister on Thursday after Boris Johnson resigned as leader of the Conservative Party.

He made a statement outside 10 Downing Street after support from his ministerial team and MPs collapsed, saying it was “clearly the will of the parliamentary Conservative Party that there should be a new leader” as he announced his resignation.

The prime minister said he tried to persuade colleagues that it would be eccentric to change governments when its popularity was only a few points behind in the opinion polls. Mr Johnson said the brilliant and Darwinian system would soon produce another Conservative leader.

Noting that the herd had moved against him, Mr Johnson said his departure had become inevitable. “I want people to know how sad I am to be giving up the best job in the world but them’s the breaks,” he said.

Mr Johnson said he was “immensely proud of the achievements of this Government”, from getting Brexit done to getting the UK through the pandemic, and leading the West in standing up to Vladimir Putin’s aggression in Ukraine.

“Let me say now to the people of Ukraine that I know that we in the UK will continue to back your fight for freedom for as long as it takes,” he added.

In a nod to his domestic agenda, the prime minister for 1,079 days said he hoped the process of increasing opportunity in the UK would continue. “We’ve been pushing forward a vast programme of investment in infrastructure and skills and technology, the biggest in a century,” he said. “Because if I have one insight into human beings it is the genius and talent and enthusiasm, imagination are evenly distributed throughout the population but opportunity is not. And that’s why we must keep levelling up, keep unleashing the potential of every part of the United Kingdom.”

There are now plenty of contenders lining up for the crown of Conservative leader, and ultimately the next prime minister.

Among the most likely to be candidates are Rishi Sunak, Liz Truss, Nadhim Zahawi, Ben Wallace, Tom Tugendhat and Jeremy Hunt. Suella Braverman has already said she would stand in any leadership contest.

Labour leader Sir Keir Starmer said ahead of Mr Johnson’s statement it was “good news” that he is resigning but “we don’t need to change the Tory at the top — we need a proper change of government”.

He threatened to use a Commons vote of no confidence procedure to attempt to oust the Prime Minister unless he hands over the reins to another premier.