Since surviving a brush with political death over the Peter Mandelson scandal in February, Keir Starmer has attempted to strike a defiant tone.

The Prime Minister has insisted in the months since that he will not walk away from No10. He has warned a leadership contest would plunge the country into chaos. He has repeatedly argued the electorate gave him a five-year mandate to deliver the change he promised the country before Labour’s landslide victory in 2024.

It was a message he delivered during the Mandelson scandal. It was a message he delivered after Labour’s crushing defeat in May’s local elections. And it was a message he delivered once again despite Andy Burnham’s Makerfield by-election win – which gave Labour MPs hope Nigel Farage’s Reform UK can be defeated.

The PM told Labour staffers on a call on Friday: “The one thing we’ve got to avoid doing is plunging our party and our country into chaos by turning on each other and tearing apart our party and our movement. That has never worked. That’s what the last government did. We need to learn that lesson.”

But this time round the Prime Minister’s message appears to have not survived contact with reality.

It is clear the mood in the party has darkened over the weekend with more MPs calling for him to go – including some of those who stood by him after the local elections bloodbath.

Crucially, Cabinet support is also draining away. Foreign Secretary Yvette Cooper and Transport Secretary Heidi Alexander became the latest senior ministers to urge Mr Starmer to step aside last week.

There has been no collective show of support from the Cabinet for the PM’s position in the wake of Burnham’s election victory. Instead – mostly – silence.

And in a stark moment on Sunday, Peter Kyle – sent out to bat for the government on the airwaves – failed to rule out the PM’s departure in the coming days.

Instead he said his boss was considering the “political realities” of Burnham’s win. We may hear the Prime Minister’s decision in the next 24-48 hours.