“The craziest Labour conference since 1985,” forecasts former Labour manager, Rob Marchant. A “free-for-all where every fantasy politics piece of ‘revolutionary socialism’ gets debated” expostulates Luke Akehurst of Labour First.

As the Labour conference approaches, the Corbynistas are gaining ground in the party. Armed with the election result, they have the political and moral capital to get what they want. Their slate for the Conference Arrangements Committee won three times as many nominations as their New Labour opponents.

But the issue that is driving the anti-Corbynistas to bilious distraction is the McDonnell Amendment. The idea behind the amendment is to lower the nominations threshold for a candidate to get on the Labour leadership ballot. Currently, fifteen percent of Labour MPs have to back a candidate for them even get on the ballot.

Given parliamentary arithmetic, that means that no left candidate. (Corbyn’s support in the 2015 nominations is unlikely to be repeated now that those who wished only to give the left “a voice” know they can actually win.) A mass, left-leaning membership, certainly the biggest since the late Seventies, risks being disenfranchised before the vote has even begun.

McDonnell, who has run twice for leader and failed to get the nominations, proposes reducing the threshold to five percent. Now there are reports of a potential compromise, with a ten percent threshold being touted.

The rationale for change is obvious. Corbyn was elected to change the Labour Party. This is the radical Left’s first ever shot at doing so, and they want to make sure that, as long as they have the support from members, they can continue the project.

Richard Angell of the Blairite lobbying group Progress complains that “with a five per cent threshold, a group of friends could get on the ballot, never mind a faction.” To which the obvious reply is: yes, and so what? If you’re going to have one-member-one-vote, why not trust members to make the choice? Why should the Parliamentary Labour Party have any veto, five per cent or more?

A pseudo-democratic rationale is offered for denying members a choice, and deferring to traditional PLP privilege. This is that members of parliament are elected by a broad swathe of voters, whereas members are a self-selecting minority in society. The former want to remain credible to their constituents, whereas the latter might choose any crazy candidate on a whim.

But this is to elide different sources of democratic legitimacy. Labour candidates are nominated by members in the expectation that they will respect the democratic decisions of the party. They are then elected by their constituents to represent them in parliament, not to choose who the Labour leader is.

The argument that members can’t be trusted with the party’s electoral interests has been a mainstay of the anti-Corbyn factions these last two years—an argument they made even while relentlessly sabotaging their own party.

They were wrong. Corbyn’s supporters understood the direction of the country better than they did, winning Labour’s biggest increase in its vote share since 1945. The presumption that the PLP knows what’s best has been tested to near-death. A little humility on their part would not go amiss.

The arguments about the McDonnell Amendment are a symptom of breakdown in party management. There is no longer a coherent story about why the PLP should have the privileges it does. Once, it could have been argued that Labour was a pluralist, federal organisation of unions, socialist societies, constituencies parties, and the parliamentary party. Many party institutions, like the NEC and the National Policy Forum, are elected on a pluralist basis. But, in a notorious irony, it was the ‘modernising’ Labour right that successfully fought to end this practice in leadership contests. Why?

Labour’s plural structures had excluded the constituency membership from the exercise of real power, which was divvied up between unions, the parliamentary party and the various bureaucracies. But when the Blairites took over, they no longer saw members as the real problem: the members seemed safely centrist, sharing the leadership’s pessimism about Labour’s electoral predicament. Instead, their objectives were to weaken the unions, who were too tied to traditional Labour priorities, and provide a plebiscitary basis for a strong leadership, liberated from the party’s elaborate checks and balances.

This was the Blairite difference: it wasn’t just a struggle against a troublesome membership, but against the whole party. Blair told Phillip Gould, “I would rather be beaten and leave politics than bend to the party.” They concentrated their forces in the senior offices of the party, where they remain entrenched, and incubated a professional stratum of party managers to fight their battles.

But they lost the argument with the members long ago—so it was a terrific irony that they achieved the Collins Review reforms in 2014, introducing one-member-one-vote for leadership contests, one year before they were crushed.

Their misfortune is to have begun a process they can’t finish, and can no longer believe in. They’re hanging on to an anachronism, the parliamentary veto, when it no longer has any convincing rationale. Either you have pluralism—or you have membership-led democracy, and take the consequences.