Is the PM about to attend his last summit of world leaders?

I am flying tomorrow to Evian in France with the prime minister for what will be the most surreal summit of world leaders of my and his career.

And that is because Keir Starmer’s tenure as prime minister is conditional on whether Andy Burnham becomes a Labour MP on Friday and then how fast he moves to unseat the PM.

Starmer and his ministers do their best in public to pretend that they are governing as normal. In private, his colleagues are explicit that he is in limbo, unable to have confidence that he will remain PM for many weeks or even days longer.

So, although this summit of the leaders of the G7 richest economies has an important agenda – re-opening and policing the Strait of Hormuz, reinforcing support for Ukraine, reducing European AI dependence on the US (so graphically manifest in Washington’s order to Anthropic to shut down Fable) – none of the leaders know if Starmer is there as the now-and-future PM or a temporary caretaker.

The PM has said that he will fight Burnham if he launches a leadership challenge. But his cabinet colleagues tell me they don’t know if that is what he feels he has to say, to maintain a semblance of authority, or whether he means it.

One minister tells me the prime minister would lose badly in a head-to-head contest against Burnham. “He would be humiliated” said the minister. “He has been told that. Whether he believes it is another thing.”

Another minister says the mortal blow was the resignation as defence secretary, John Healey. Before Healey revealed himself to be unwilling to serve a PM unable to find the money deemed necessary by Healey to mend the UK’s overstretched defences, ministers were reluctantly rallying around Starmer. No longer.

“What was half-hearted support for the PM has more-or-less gone,” said the minister. “He could try to replace those ministers he feels have been most disrespectful to him, like Ed Miliband and Shabana Mahmood, but that would probably be the final nail in his own coffin.”

Starmer is seen as isolated from most of his colleagues, seeking solace and advice from his attorney general Richard Hermer and his former chief of staff, Morgan McSweeney – whose informal return to the centre of government alienates many Labour MPs, because of his central role in the debacle of Peter Mandelson’s stint as British ambassador in Washington.

This period in purgatory will stretch through this week, but ministers believe the moment of Starmer’s fall or redemption will be next weekend.

If Burnham wins decisively in Makerfield, reversing the seemingly decisive shift to Reform of the local elections just a few weeks ago, ministers expect that Labour MPs will want an orderly transition from Starmer to Burnham, without the chaos and uncertainty of a lengthy contested leadership election.

Burnham and Starmer will therefore engage in a political dance, assessing how far the other will go to take the party to the brink of that messy contest.

What happens if they can’t agree a transfer of power, if Starmer does what he says and insists Burnham puts up in a formal contest or shuts up?

“That status quo could not last,” says a minister. “The prime minister’s authority is too weakened. There would be a contest, maybe triggered by another candidate.”

The prime minister is said to be plotting a survival strategy, as if it were a game of chess. But none of his colleagues – or at least those to whom I have spoken – think he can win.