Last week, as Labour’s national executive voted 17-15 to hold a secret vote on whether or not Jeremy Corbyn should be on the leadership ballot, the atmosphere in the Momentum office reached fever pitch. Desperate schemes were thrown around to "love bomb" MPs to get them to nominate Corbyn (“we could get Jeremy to make a batch of jam and give them all jars”; “quickly, dig up anything good a Labour MP has ever done, we can make memes out of it”). But above all there was genuine disbelief: the most desperate elements of the Labour Right had hatched a plan which, if successful, would have plunged the party into a nightmare from which it would never recover. Surely the NEC wouldn’t, couldn’t, go for it.

And they didn’t. Jeremy Corbyn is safely on the ballot for the leadership election and is the favourite. His supporters, however, should not delude themselves – because even in defeat, last week’s manoeuvre was powerful. Demoralisation is an integral part of the Corbyn challengers' plan. Every briefing, every character assassination, every outrageous plot is part of a chaotic choreography: an attempt to convince the membership that, however much they may agree with Corbyn’s politics, he cannot lead a divided Labour to victory.

Electability may just be a cover for real political differences, but it is the Labour right’s only viable argument, and the left needs an answer to it. If Corbyn were to lose, it would not be the first time that the Labour establishment had persuaded the labour movement’s rank and file that principles and power don’t mix. Last year’s landslide was a massive accomplishment. But in a two horse race, as this has become, a majority of 9.5 per cent is not a safe one.

We need an electability narrative of our own – one that goes beyond the idea that Labour can simply recruit its way to victory. Broadly speaking, it’s this: in a political climate still shaped by the 2008 economic crash, the only ideas that can make sense of the world are those which have a systemic critique of capitalism. Popular support for Corbyn’s basic domestic policies – wealth redistribution, common ownership, opposing austerity, tackling corporate power – was already very high before he won the leadership and has been rising since. The big task for the new Labour leadership is to bring this programme to life in the context of an automated, rapidly shifting 21st century economy, and take it to the country with a massive new army of activists.

All over Europe and the developed world, centrist social democracy is in disarray. The historic compromise made between the Labour establishment and neoliberal economic policy has been bankrupt for some time – and not just intellectually.

If we really want an honest healing process, maybe Labour should admit that across the country, and among Labour’s voter base, there are people on benefits, on poverty pay, and on housing waiting lists whose lives got worse under the last Labour government. Sitting on BBC sofas at the weekend, Owen Smith and Angela Eagle agreed on their line: “Austerity is right, but we need a plan for prosperity."

Just as in last year’s contest, Labour’s centrists lack any strategy beyond desperately triangulating their instinctive support for austerity with their membership’s actual views, with Angela Eagle even making a lack of political content a defining theme of her campaign.

As a result, the Labour right has to focus not on a strategy to win elections, but on an apocalyptic narrative around the electability of the left. In May, Labour broadly held onto its 2012 support levels, and won a series of significant mayoral elections. Labour’s performance has not been a runaway success, but to make this narrative stick, the centrists would need the party to be doing a lot worse than it is.

Smith’s support for a second EU referendum – or a general election where the terms are clear – is another case in point. Corbyn must be wary of falling into this trap. Smith knows that large chunks of Labour’s membership are mourning Remainers – and we must not be blasé about the genuine democratic need for a clear mandate for what comes next. But this response to the aftermath of Brexit is merely centred on process, rather than addressing the core reasons why so much of Labour’s base voted the way it did.

There are many obvious ironies in Labour’s internal strife. The left are accused of wanting power in the party but not in the country. The right wage a raw struggle for internal power, without much regard for Labour’s unity or electoral performance. The left call for loyalty to the leader. The right launch an electability crusade and then refuse to put forward their most talented candidates. But the greatest irony is a much bigger one - bereft of ideas, Labour’s centrists just aren’t electable at all.