Starmer remains defiant as leadership challenge inches closer

Sir Keir Starmer's survival strategy has notched up yet again, with further defiant talk aimed at raising the political barrier as high as possible for his potential challengers to clear.

I have sat down with the prime minister twice in the past week. First, last Friday, when I was invited into 10 Downing Street for a longer interview than usual.

And again today, for a shorter question and answer session as part of a round of interviews with broadcasters at the G7 summit in the French Alps.

He had clearly decided that even if he wasn't asked directly, he would, as he put it to me, "gently point out that we do have a Manchester mayoralty by-election which will follow immediately, if Andy Burnham wins the by-election".

This was a reference to the fact that the mayor of Greater Manchester cannot be a sitting MP, meaning a Burnham victory would create a vacancy in one of the plum roles in devolved English politics.

Starmer was effectively saying that Burnham's first priority if he wins should be to ensure Labour holds the mayoralty, rather than plotting his own route to No 10.

In other words, the prime minister was seeking to play for time – and point out to the Labour Party that Burnham caused the Makerfield by-election, and will trigger another one if he wins.

Even if Labour hold both, they are only back to where they started in terms of the seats and offices they hold.