Why no mention of London mayor Sadiq Khan?
You need to be an MP to run for leadership. But if he seriously wants the position, I'm sure he has an ally or two in a safe labour seat willing to start an immediate by-election for him. If Corbyn allows the party time to reflect, than Khan has more time to make the moves to rejoin parliament. He probably easily passes all the other requirements since a serious chunk of London would be behind his candidacy, and there's more than enough Unions and party machinery there. Him joining would be a case of doing all the secondary steps first, and then running for a Westminster seat with the understanding that he's an immediate candidate from day one.
Khan however has two downsides behind the obvious 'not being a MP.' Number one, hes a man. Number two though is more important. Selecting Khan would send a clear signal that the north would remain on Labour's backburner. Khan can have a 'forwards' (not looking back ideologically but finding something new) style vision that reinvents Labour for the 2020s, but his vision is all about the Global Cities and their commuters. Ideally, rebuilt Labour's vision has a place for their northern communities alongside the expanding internationalists who want to get away from SNP/Tory nationalism.
Downside 3 for Khan is he's a practising Muslim. Islamophobia is pretty prevalent in some form in the white working class and some of his pre-MP actions as a solicitor are the sort of thing that would be misrepresented - they're not exactly Corbyn stuff, but the right-wing media will take what they can get.
Downside 4 is that I doubt Momentum would like him for his dislike of Corbyn,
Downside 5 is that his mayoralty has seen some fairly big issues at Transport for London and a spate of knife crime.
He has his drawbacks, but at least anti-Semitism isn't one of them (admittedly surprising for practicing Muslims these days):
Sadiq Khan joins Zionist Jewish Labour Movement
