Hopi Sen has ruled himself out.
John Sweeney is presumably precluded by his BBC employment.
So that leaves only James Lyons to put up or shut up against Ian Lavery in 2020.
Yes, that seat does have its second MP in a row to be left-wing, an ex-miner, and the owner of an Irish surname.
Since you obviously object so much to each and all of those features, then let the electorate decide whether or not it agrees with you.
Very much like Nick Cohen and the forthcoming Tooting by-election at which George Galloway is already a campaigning candidate even though the vacancy has yet to arise formally.
Put up, or shut up.