For that to happen, Starmer (and anyone else) would have to step aside and not fight to stay in power.
But is Burnham actually any good? and whilst polling is better now, how long would that last before the media turn on him plus the fundamentals of the economy haven't changed.
Immigration esp x channel, is the top priority for the electorate, that needs addressing, regardless of Reform.
Can see the potential issues, just reading this thread...