Also good that the way in which party candidates are selected is treated as a constitutional issue of importance to all of us - not just members of the party concerned.
In the absence of PR (which makes it hard for breakaway parties or unofficial candidates to stand against the official candidate, and makes most seats one party fiefdoms) the question of who chooses the candidate is rather important, democratically.
My own view is that it just isn’t enough to confine that choice to party members (let alone activists): the case for an open primary system is strong.
NB I don’t take that view because I think the candidates would be likely to be more “moderate” if you had primaries: see the US (or, indeed, Corbyn, given the relative openness of the Labour leadership election).
It just seems to me to be about democratic principle, and an acknowledgement that the main parties aren’t private clubs whose choices are of no concern to anyone else (particularly as first past the post entrenches, and is designed to entrench, their position).
