British Prime Minister Keir Starmer was weighing the "political realities” facing his government, a senior minister said Sunday, amid media reports that he could resign within days.

This follows veteran Labour politician and rival Andy Burnham's victory in a by-election Friday, which paves the way for the 56-year-old to challenge Starmer for party leader and prime minister.

Any Labour leadership candidate must be a member of Parliament.

If Starmer leaves office this year, Britain will get its seventh prime minister in a decade – an unprecedented rate of churn in its modern history.

Burnham, Greater Manchester mayor since 2017, made clear his intention to bid to lead the center-left party, warning in his by-election victory speech that it had a "final chance to change." If successful, he would become prime minister, given the ruling Labour Party's large parliamentary majority.

Starmer, who polling shows is unpopular with voters, insisted he would fight any attempt to oust him. But Burnham's emphatic win in the Makerfield constituency in northwest England, where he nearly doubled Labour's majority, increased internal pressure on Starmer to quit.

Business Secretary Peter Kyle said Sunday that Starmer was "making time to reflect on the political realities, challenges and opportunities that he finds himself in."

"He has been engaging in conversations with a wide range of people," Kyle told Sky News after having what he said was a "frank" conversation with Starmer Friday.

Resignation reports

The Observer reported Sunday on its front page that Starmer was "expected to resign" Monday, while The Sunday Telegraph also reported he was "ready" to go, citing allies of the British leader.

The Observer said Starmer would "set out a timetable for his departure," noting he held weekend talks at Chequers, the prime minister's country retreat.

Foreign Secretary Yvette Cooper was among the senior ministers telling her boss to stand down, Sky News reported.

Starmer, who took office some months ago, clung to power after a tenure littered with missteps, policy U-turns, scandals and ministerial resignations.

He was nearly forced out in March over his decision to appoint former Jeffrey Epstein associate Peter Mandelson as Britain's ambassador to Washington.

Labour's losses in local and regional polls in England, Scotland and Wales last month again intensified pressure on him. The fallout from the polls prompted Makerfield's previous Labour MP to resign to allow Burnham to stand there.

Burnham, a former MP and government minister under former Prime Ministers Tony Blair and Gordon Brown, is scheduled to be sworn back into Parliament Monday.

A member of Labour's soft-left wing, he reinforced his reputation as the party's most popular figure after easily beating the candidate for the hard-right populist Reform U.K. party in the by-election this week.

Reform, led by Brexit architect Nigel Farage, won all wards in Makerfield in local elections there last month.

Burnham has provided little detail about his plans for government if he wins power. British media reported he intends to replace Finance Minister Rachel Reeves while keeping Interior Minister Shabana Mahmood in her post.