Keir Starmer is facing the political equivalent of a vote of no confidence from the universe, as potential successors from Wes Streeting to Angela Rayner have begun limbering up for a leadership contest that feels less like a transition and more like a particularly awkward family reunion.

Starmer was hoping to save his skin with a vision-setting speech on Monday, but his chances of remaining in No 10 were looking about as sturdy as a sandcastle at high tide on Sunday, with roughly 40 Labour MPs - many of them fans of Greater Manchester's mayor Andy Burnham - calling for him to name his exit date.

The chaos follows a local election bloodbath where Labour lost support to Reform UK and the Greens, prompting one ally of Streeting to note, "Wes isn't going to challenge Keir but he is preparing in case it all falls apart." The health secretary has reportedly delivered this same message to No 10, though he apparently wants someone else to push the first domino.

Rayner, the former deputy PM, has already set out her prescription for change, warning Starmer he needs to "meet the moment" - which is politician-speak for "I'm ready if you're not." Her supporters insist she isn't definitely running, but she's definitely prepared for the possibility, which is the political equivalent of having your bags packed by the door.

Burnham remains the dream candidate for many, provided he can actually get back into parliament. If that doesn't happen, the left flank may have to fight over his endorsement like kids squabbling over the last slice of pizza.

Catherine West, a Labour backbencher, is pressing ahead with a "stalking horse" challenge - a tactic designed to flush out other candidates - by trying to gather 80 supporters to trigger an immediate contest. Burnham's allies are reportedly trying to persuade her to withdraw, because her timing would benefit Streeting, not their guy. "It's not gone to plan. This wasn't meant to benefit Wes," one Burnham-supporting MP lamented, while another described West's intervention as chaotic and "like one of those free-running horses at the Grand National."

Education secretary Bridget Phillipson gamely defended Starmer on the BBC, saying it would be wrong to remove him even though voters gave the party a "real kicking" and people feel "bitterly let down." But few MPs seem to think Starmer can regain his authority. One cabinet source put it bluntly: "There is a residual loyalty to Keir but [the cabinet] are at end of their tether."

Starmer, for his part, told the Observer he wants to serve two terms or 10 years - a statement that elicited the sort of laughter usually reserved for stand-up comedy. He's also tried to refresh his government by bringing back former PM Gordon Brown as a finance adviser and former deputy leader Harriet Harman as an adviser on women and girls, which is a bit like calling your exes for relationship advice.

Meanwhile, the Labour Growth Group is preparing to present its blueprint for "a new economic settlement," calling for higher capital gains tax to fund a 2p cut to national insurance. One government minister warned: "Labour can still win in 2029, but only if we turn warm words about working people into radical and urgent action."

Rayner released her own economic renewal proposals, saying, "What we are doing isn't working, and it needs to change. This may be our last chance." She also warned the party is in "danger of becoming a party of the well-off" and called out the "toxic culture of cronyism" exemplified by the Peter Mandelson scandal.

Some on the left are urging Ed Miliband to throw his hat in the ring, believing Rayner doesn't have enough national support and that her unresolved HMRC tax inquiry is a liability.

For now, the cabinet remains largely silent, having not yet issued public statements of support after Labour lost 1,500 councillors and about 40 councils. No ministerial resignations have materialized yet, but the clock is ticking louder than a time bomb in a thriller.