From the outside, the debate within Labour around “mandatory reselection” looks decidedly odd. In the Scottish Greens we don’t call it that: we just call it “selection”, and to my knowledge no-one has ever suggested not doing it before each and every election.

As a non-Labour member who’s spent almost two decades selecting and helping to elect candidates each time, the alternative is too weird to contemplate. What if we elected someone and their politics took a radical shift away from the views of the branch? Is there really no situation in which we would ever want to be able to pick someone else for a seat we’d won five years before? What if someone “went nuclear” or got an obsession with population?

Fundamentally, it’s a question about who the nomination belongs to, and each and every time it should belong to the party’s local members. Only they should be able to decide whether someone gets the party logo next to their name on the ballot paper.

And that brings advantages. What candidate wouldn’t want to know that their local branch had endorsed them again? The alternative is potentially an increasingly disengaged and disgruntled activist base, reluctant to work to re-elect candidates they have no say over.

MPs, MSPs, councillors and the rest should always be accountable both to the party that nominated them and to the public who elected them. To get in the first time you need both. Why should that change for any subsequent election?

I should say that in the Scottish Greens, at least, I’ve never seen a sitting candidate overturned for someone else. It’s much easier to build and enhance your profile as an elected member, which again makes me wonder what the opponents of internal democracy in other parties have to fear.

The requirement to work to retain the support of your members isn’t a massive burden, and no doubt many Labour MPs do it anyway. But selection each cycle undoubtedly increases the extent to which elected politicians engage with the local membership as well as their electorate.

Observing this debate from the outside it often gets billed as a Labour left versus Labour right debate. And as the leadership elections and shadow cabinet resignations show, Labour members are clearly to the left of many of their MPs.

But a shift of this sort wouldn’t lock in control by the party’s left: it would lock in control by the membership. It might well have made life awkward for some MPs in the Campaign Group in the early 1990s, for example, as the Blairite wave swept through the party.

In fact, it would avoid a problem particular to the current arrangement. A leader, backed by the membership, wants to shift policy, but even if they win, the safest seats will be represented by people chosen by a different membership, under a different leader, sometimes more than one political era ago. If you wanted to devise a system that increased the risk of both division and inertia it’d be hard to beat Labour’s status quo.

And there’s a reason why the Tories are the only major party other than Labour that doesn’t select for each election. They don’t trust their membership, which may be understandable, but it also reflects one key aspect of Conservative ideology - the idea that you must just trust your social superiors.

Parties that don’t trust their members are also unlikely to trust the public, and it shows, sometimes explicitly, other times implicitly. It’s a bad look, especially for a party that pitches for left votes. Selecting each time is hardly a far-left Green foible, either: the SNP and the Lib Dems operate in this way too, and the process doesn’t appear controversial in either of those parties.

Selection is one of the two key responsibilities that members of any party should be able to take for granted, alongside democratic policy formulation, another contested issue within Labour. Personally, no matter how much I agreed with a party’s political positions, I wouldn’t join it unless I could take part in those two fundamental processes. Members aren’t obstacles to be worked around or assets to be cajoled out just before each election: they are a party’s keenest voters, their current activists, their potential activists, and their potential future elected politicians. They will also be the best source of innovative campaigns and policy initiatives. Listening to them and giving them their say keeps a party honest and responsive.

I don’t have a dog in the policy fight within Labour, of course. Indeed, from a partisan point of view, a Labour Party which alienates and ignores its members would probably be good for the Greens. But this debate continues to astonish me. Every party should let its members pick their candidates at every election, and I believe Labour (and even the Tories) doing so would lead to a better-functioning democracy for everyone. Above all, the alternative should be intolerable for anyone to accept.