British Prime Minister Keir Starmer was struggling to hold on to power after his main rival in the government resigned on Thursday, accusing him of political drift, and others positioned themselves for potential challenges to his leadership.

Disastrous results for the governing Labour Party in local elections last week have plunged Britain into a new crisis, just under two years after Starmer won a large majority on a vow to bring stability and end a decade of political chaos.

After days of calls by Labour lawmakers for Starmer to quit or set out a timetable for his departure, Wes Streeting resigned as health minister, the first senior minister to break cover. He said he was standing down because “it is now clear you will not lead the Labour Party into the next general election”.

But Streeting did not trigger a formal contest, and other senior cabinet ministers expressed their support for Starmer.

Labour members of parliament and trade unions said they wanted the debate about what comes next to focus on ideas rather than personalities or factions, his resignation letter said.

“It needs to be broad, and it needs the best possible field of candidates,” Streeting wrote.

Greater Manchester mayor Andy Burnham, like Streeting a Labour Party politician, said separately he would seek a seat in parliament – a move that could pave the way for him to challenge Starmer.

Streeting says Britain needs vision

“Where we need vision, we have a vacuum. Where we need direction, we have drift,” Streeting said. “Leaders take responsibility, but too often that has meant other people falling on their swords.”

Starmer responded with a letter expressing regret Streeting had stepped down, saying “it is incumbent on all of us to rise to what I see as a battle for the soul of our nation” and “turn the page on the chaos”.

A source close to Streeting said the former health minister had enough support to mount a formal leadership challenge but had not triggered an immediate contest because he felt it would be preferable for Starmer to set out an orderly timetable.

Starmer has said he will battle to keep his job, and sources close to him say he is determined to fight any leadership contest.

The pound edged lower after Streeting’s resignation and news that Burnham would seek to return to parliament.

“It moves us one step closer to a Labour leadership challenge. How many steps are between here and there, that’s still uncertain,” said Nick Rees, head of macro research, Monex Europe, London.

Earlier on Thursday, Starmer’s former deputy, Angela Rayner, said she had been cleared of deliberate wrongdoing over her tax affairs, an impediment to any leadership contest, but she would not say whether she wanted to launch a formal bid.