I think Starmer will stay on just by refusing to move 🤷. Burnham has nothing to offer. Burnham will have to agree to fiscal rules, foreign policy etc to seem Sensible. And Starmer can just play the stability/Statesman role and say it's the wrong time for a leadership challenge #twopenneth
So far, during this World Cup (all 70 mins of it), Beckham, on American TV, has advertised Lays, Home Depot and Verizon.