TBF, unless a challenger throws his/her hat in the ring, the decision to resign is Starmer’s alone. If he thinks he can govern with Labour in its current state then he can carry on.
I think he’s horribly wrong and is poisoning Labour’s chances, but he does at least keep Miliband or Rayner out (assuming the tax issue didn’t dissuade her) and can cross his fingers and hope Burnham fails to get a seat. I assume the NEC would still have to agree Burnham - what a laugh that will be.
It seems increasingly clear that Streeting would split the party and face dissent from day one.
I must admit that I’m surprised at the strength of anti-Streeting reaction within Labour. But then you can never overestimate the aggressiveness and spite of the Labour left.