Although Starmer vowed to fight on after a bruising week in which one cabinet member resigned, dozens of MPs called for the United Kingdom's prime minister to quit and his new policy proposals were largely ignored, some observers believe it is only a matter of time before he steps aside.
The message of the past week "is that Labour seems to have made up its mind that Keir Starmer is going to have to go," said Tim Bale, a professor of politics at Queen Mary University of London.
"And he's going to have to go reasonably quickly, and he's going to have to be replaced by someone who can, unlike him, connect with the public."
Speculation about Starmer's future broke into open rebellion on Thursday when Health Secretary Wes Streeting resigned in preparation for a possible a leadership bid and the mayor of Greater Manchester, Andy Burnham, declared his intention to return to parliament.
Former deputy prime minister Angela Rayner announced she had cleared up a tax issue that forced her to resign from the cabinet last year, thus freeing her up as well.
Starmer is under growing pressure to step down after Labour performed dismally in local and regional elections last week, hemorrhaging votes to both the populist Reform UK party and the progressive Green Party.
The electoral drubbing cemented doubts among many party members about Starmer's judgment, vision and leadership less than two years after he led Labour to a landslide victory.
But the potential contest to unseat him is on hold for now as the party waits to see if Burnham can win a by-election for a seat in parliament that would allow him to enter the race.
If he returns to the House of Commons, Burnham is widely expected to challenge Starmer.
On Friday, Labour's executive body approved Burnham to run for the seat that became available when a Labour MP resigned to make way for the Greater Manchester mayor.
The by-election is expected to be in the next five or so weeks.
As and when a challenge to Starmer emerges, Labour's National Executive Committee will set the timetable for any leadership election.
The most recent contest lasted three months.
The government's borrowing costs rose on Friday and the pound weakened on investor concern about continued disarray in Westminster.
The pound has dropped 1.3 per cent against the US dollar this week.
Housing Secretary Steve Reed on Friday appealed to party members to step back from the brink of a divisive leadership contest that he said would prevent the government from tackling issues like the cost of living and bolster the prospects of Reform UK.
"This weekend people just need to take a breath, look at what's gone wrong this week, and come back next week ready to do what we said we'd do - country first, party second - and focus on delivering the change we were elected to deliver," he told the BBC.
