John McDonnell was insisting this morning that Labour was going to win a majority, but just in case, insiders are suggesting that the Shadow Chancellor is planning to take over as interim leader if Jeremy Corbyn resigns after a general election defeat. McDonnell has long championed Rebecca Long-Bailey as a future leader, and there is speculation that he could install her as his shadow chancellor in order to boost her credentials.
This explains why those around Corbyn were so keen to try to abolish Tom Watson as deputy leader in September. They tried to force a rule change at the party's ruling National Executive Committee meeting which would scrap the post. It was pulled after a big row an an intervention from Corbyn, but Watson stepped aside when the election was called anyway, meaning that he has been removed as a potential blockage to the Corbynites getting their way. The 'moderate' Labour MPs who saw Watson as the keeper of their Labour flame had expected him to take over as caretaker leader in the event Corbyn left, as is constitutionally the convention in the party. But with no deputy leader, the succession is clear.
It's not entirely clear whether Long-Bailey would succeed, despite McDonnell's support. Other contenders include Laura Pidcock, supposedly the favourite of Corbyn's close aide Karie Murphy, and Emily Thornberry or Keir Starmer, both of whom have stayed strangely quiet during this election campaign, almost as though they expect the party to lose and think there might be something to be gained from not being too closely associated with that loss.
Their calculation depends on members blaming the leadership for losing, though. As we have seen, activists did not return from the 2015 doorstep thinking that the solution to Labour's problems was to be less obviously left-wing. Instead, they seemed to have heard something rather different, and elected Corbyn as leader. Even Ed Miliband himself now remarks to colleagues that he sees Corbyn's success in shaping the political debate as a sign that he should have been more radical as Labour leader. There are so many people to blame for a loss this time - the media, lying Tories, 'smears' about anti-Semitism, money, the weather, Trump - that those around Corbyn may have their dignity intact even if the leader finds himself resigning in the aftermath of Thursday's poll.