I am one of those people who find it difficult to consider things fully in a vacuum. I find it much more useful to put out ideas and retreat from or firm up on them through discussion. A few days ago, I put out the idea that I didn’t think Jeremy Corbyn had done so well as to justify automatic support in a possible leadership challenge. I’d have to see what the alternatives were.

I am now quite sure that Corbyn needs to go.

A reasonable enough position, I think. It is the precise process via which I arrived at Jeremy Corbyn during the last contest, after all. The reaction I have faced from the Corbyn faithful – a frightening mix of superficiality and viciousness – has actually pushed me in the opposite direction. I am now quite sure that Corbyn needs to go.

What started as a grassroots movement has become a personality cult. “It is not about Corbyn, but the new politics he represents” say his supporters, while simultaneously decrying as “snakes” and “Blairite scum” anyone who has the nerve to offer any critique of his approach. The level of denial of fact combined with the evangelical attachment to him personally and underlying threat of violence complete with “traitor” rhetoric, is reminiscent of Ukippers’ attitude to anyone criticising Farage.

And there is also a Ukip-like denial by more “reasonable” supporters of the nastiness that seems to have corroded the movement from the inside. With every aggressive tweet, with every insult, with every Canary blog, with every labelling of anything inconvenient a Blairite plot, I became more and more convinced that “Corbynism” was not the answer. Anything “ism” isn’t.

If the attitude towards a Corbyn supporter expressing some doubt is to shout “DIE TRAITOR! CORBYN FOREVER!” what is the more general electoral strategy towards people who were never convinced about him in the first place, let alone floating voters? Punch them in the face, presumably, unil they agree that “JC is the best”.

I supported Jeremy Corbyn strongly and vocally. I like his politics. I think he has done a very important job in opening up conversations – like the renewal of the Trident programme or renationalisation of industries which are provably unsuited to competition – that had hitherto been inexplicably closed for debate. Those discussions can continue. He has ensured that the next Labour leader will have to speak to the whole party.

He has stumbled from blunder to blunder, has behaved with intransigent vanity and mumbled his way to Brexit.

One does not need to be a Blairite, however, to notice how ineffective Corbyn has been at the actual job of communicating the Labour message and leading his team. He went into the leadership promising to build bridges and has ended up alienating even close allies. He has stumbled from blunder to blunder, has behaved with intransigent vanity and mumbled his way to Brexit.

The argument that he delivered a high proportion of the Labour vote for Remain is misconceived. It means nothing without a baseline. Is two thirds good? What are we comparing it to? The other claim is that he delivered the youth vote. A high proportion of young people voted for remain. But only a minority of young people voted at all.

We can never know whether these stats could have been improved. I can, however, assess his performance. I found it lukewarm and half-hearted. His refusal to share a platform was disastrous. Andrew Neil has said that he refused one-to-one interviews, too. His only major television appearance was on a comedy show, during which he droned on about his pet obscure directive on “posted” workers. His ambivalence was plain for all to see. And I don’t think it is a coincidence that there seems to me a significant overlap between those who still support him and the misguided “Lexit” camp.

I am also quite fed up with cries of “coup” and “backstabbing” and how all this is “undemocratic” and “unconstitutional”. Corbyn is on record as saying that it is MPs’ duty to rebel against their leadership if they disagree. Few MPs have his record of defying the whip. He was instrumental in attempts by Benn to destabilise first Foot, then Kinnock.

Corbyn promised to convince, rather than coerce. It was an attractive notion. But he has done neither.

I’m not criticising any of those things. His rebelliousness was part of the reason Corbyn was an attractive prospect in the first place. But let him show some intellectual consistency. He can’t embody those things for his entire career, then morph into some sort of Kim Jung Jez figure, the moment he has power, demanding unquestioning loyalty. Corbyn promised to convince, rather than coerce. It was an attractive notion. But he has done neither.

There is nothing unconstitutional or undemocratic about MPs voting to say they have no confidence in their leader. It is just about the most democratic expression of dissatisfaction there is. Corbyn followers wilfully ignore half the process of electing a new leader. MPs are explicitly written into it. It is only a person who can secure a certain percentage of support that goes to the more general vote. Why do they think that is?

Is it possible that the system recognises some MP support is absolutely instrumental to the job of leader. Corbyn refuses to resign, because resigning would relinquish the debatable right to be on the ballot automatically. But he would only need 15% of nominations to get back on the ballot. Isn’t the fact he is not sure he could even secure that the most telling of all? Instead the unions supporting him threaten deselection. Now, that is undemocratic. That is unconstitutional. It is plain blackmail. It is the opposite of the “new, kinder politics” that he promised.

Everything has changed. We live in a country where the majority just voted for isolationism, regression and economic self-harm effectively on the basis of “experts, schmexperts”.

All this I could forgive. But the denial of post-referendum reality, by both Corbyn and his faithful, is unforgivable. “Don’t lose your nerve”, they say. “Stick to the plan. Nothing has changed.” Everything has changed. We suddenly find ourselves facing the possibility of a General Election within months; facing the probability of Britain exiting the European Union. An almost inevitable recession and, by extension, more austerity looms. Project Corbyn has run out of runway.

Maybe there had been an opportunity for a fresh, clean anti-austerity, anti-establishment message to break through. I believed this, that’s why I voted for Corbyn – for that message. But the more radical the message, the more effective its communicator must be. Corbyn’s manifesto is simply mismatched by his ability to explain it. He is an inexperienced diver, attempting a 3.8 difficulty manoeuvre. We cannot deny we live in a country where the majority just voted for isolationism, regression and economic self-harm effectively on the basis of “experts, schmexperts”.

Labour was probably snookered anyway. Has been for a long time. It should have introduced proportional representation while it still could in order to unite progressive voters everywhere. The things demanded in different regions are plainly irreconcilable. It faces existential threats, by parties who can focus their message and give those regional voters what they want. SNP in Scotland, PC in Wales, Ukip in the North of England, Conservatives in the South, Liberal Democrats in London.

… the next election will be fought on membership of the European Union.

Suddenly, however, there is a glimmer of an opportunity: the next election will be fought on membership of the European Union. Some contenders will offer definite Brexit. The Conservatives – by their recent act of Boricide – appear to be firmly in this camp. Others will need to offer a backdoor opportunity to reconsider – perhaps by virtue of full Single Market membership or a second referendum on the actual terms of Brexit. There is a rich constituency of 16 million Remain voters out there, to which buyer’s remorse adds every day.

Corbyn would be thoroughly unconvincing arguing either position – he is unconvincing arguing most things at the best of times anyway. But by half-heartedly arguing against his own beliefs during the EUref campaign he has shot himself in stereo. He can no longer be a compelling voice on either side of what will surely shape up as the central issue of the imminent election.

His supporters seem to have galvanised around the notion that, with things as they are, it is absolutely the wrong time for Labour to be looking inwards and engaging in a damaging leadership challenge.

I disagree. The Tories being involved in their own Game of Thrones, the legislative programme entirely frozen, and the news cycle spinning so quickly that even a PM’s resignation is forgotten two days later, provide the perfect opportunity. Indeed, unless Labour open their eyes to the challenging, changing reality around them, it will be the last opportunity.

I was willing to give Corbyn space to grow. He has shrivelled instead. I was willing to give him time to develop his message. There is no time now.