It doesn't matter who. Either is fine by me, the other as deputy.
But that won't happen before Makerfield. Which may let Burnham in. That may not be a bad thing, he'll be just as terrible as the rest and then can't be held up as the almighty socialist dream PM we never had.
If Burnham doesn't get in now then he'll probably become leader at some point, by whatever devious means. In time for the election after Reform's first term. It's best we experience reality before then, or some will still believe he's the saviour of the nation.
The bond markets will erupt as soon as he becomes PM, so it should be over pretty quickly. He's already said he's going to increase spending and borrowing, which just isn't possible now.