The split between Diane Abbott and John McDonnell is reminiscent of the one between McDonnell and Michael Meacher in 2007. On that occasion, Meacher stood aside and endorsed McDonnell, although the latter still didn't make it on to the ballot paper.
Now, after McDonnell's ill-advised claim that he regrets not "asassinating Thatcher" (it was obviously a joke, but it showed why a lot of people don't take him seriously), there are calls for the Labour left-winger to stand aside to give Diane Abbott a chance of reaching 33 nominations.
Under Labour Party rules, MPs can nominate an alternative candidate if their original choice steps down before nominations close. As things stand, Abbott has eight nominations, while McDonnell has ten, though the former may pull ahead after yesterday's hustings (our own is tomorrow night). There are also six members of the Socialist Campaign Group who have yet to nominate a candidate and are likely to support either Abbott or McDonnell.
It may seem strange for McDonnell to be facing calls to stand aside. After all, with more confirmed support than Abbott, why shouldn't he be asking her to do the same?
But this argument ignores the fact that Abbott's potential support is greater than McDonnell's. There are a number of Labour MPs who would like to see a female candidate on the ballot but won't consider nominating Abbott until she has a realistic chance of proceeding to the next stage. By contrast, many Labour MPs consider McDonnell beyond the pale, due to past acts such as praising the IRA.
Abbott's presence in the contest would force the other candidates to engage with the sort of arguments on privatisation, Afghanistan and inequality that they have avoided for too long.
In an article last month McDonell wrote:
[I]f at the end of this fortnight my standing down would mean securing any woman on this ballot paper, or any black person, of course I will do so.
It may be time for him to do just that.