If I was to list the areas on which I see things a bit differently from Diane Abbott then this might be a very long blogpost.
Nominations are not votes. I do hope Labour MPs - whoever they are going to vote for and publicly support - will try to ensure that they give sufficient nominations to give a place on the ballot to a voice in this leadership contest who can offer a perspective which is not that of a former Minister. (I am assuming that both Milibands, Ed Balls and Andy Burnham have declared in the knowledge that they can secure the 33 nominations they need to run, though this may not yet be guaranteed in every case).
John McDonnell could also prove a left voice.
It is not really my place to get into a detailed debate within the Campaign Group left about which candidate should run. It would also be a good thing if there was not an all male contest, but that is not only the responsibility of the party's left flank.
So I do hope that most Abbott or McDonnell backers would also be willing to back the alternative candidate if they are most likely to get into the contest, rather than having two insufficient groups of nominations. And perhaps Tony Lloyd as the Chair of the PLP could try to actively gather together MPs (whether pledged to support other candidates or not) who are interested in making nominations in the cause of a broader and more open contest, and who could then offer a pool of MPs who might consider "topping up" candidates who fall a little short just before deadline day.
Few people have noticed that McDonnell has one slight "experience" edge on the other candidates as the only one to attempt to contest the leadership before. He did not get the nominations to run in 2007 - but, despite that, he does therefore start out with experience of having husted for the leadership, in the Fabian Society debate between Gordon Brown, John McDonnell and Michael Meacher just before nominations opened in 2007. The hustings transcript can be read here.
In particular, Abbott is very critical of my take on race politics - especially in that she is among the most prominent champions of all black shortlists, which I think would now take us backwards. That reflects a substantial disagreement about a range of related issues, though I am very clear that those critical arguments are only in play at all because of the breakthrough made against enormously higher barriers by Abbott and the class of 1987.
If she runs, I may well get the chance to disagree with her approach to increasing diversity in our politics. But it would be a good thing to get to hear the arguments about that and many other issues in the leadership campaign.