Top potential candidates are Rishi Sunak, Liz Truss, Jeremy Hunt, Sajid Javid, Ben Wallace, Penny Mordaunt, Penny Mordaunt and Tom Tugendhat.Aren't we likely to just see the same people who threw their hat in last time, plus maybe a few new ones?
Liz Truss was a favourite last time if I remember right, though she's stood by Boris through this (? I think) so that may have knocked her down a bit
Jeremy Hunt was a very close second to Johnson in the last leadership challenge, there wasn’t that much in it, but Johnson won. Gove was third, but quite a long way behind Johnson and Hunt.