The only thing ‘Dispatches’ revealed was that Owen Smith has done more to help Momentum than he’d care to imagine

Corbynistas were given another reason to organise by the fruitless challenge by Owen Smith after the EU referendum. Without that, Momentum wouldn’t have been sitting in Unite’s office hitting the phones to strengthen both Corbyn’s position and their own

The contest also allowed Corbyn to stay in his comfort zone (Reuters)

As voting closed in the Labour leadership election on Wednesday, one of Jeremy Corbyn’s exasperated critics sighed: “Same time, next year.” His enemies within already plot another leadership challenge, the third election in as many years. So we should take talk of truces and olive branches after Corbyn’s re-election is confirmed on Saturday with a bucket of salt.

Labour is two parties but not yet ready to divorce. Neither wants to hand over the house to the other. Its loveless marriage will continue, at least for a while. A split could happen, but is unlikely before the general election due in 2020.

Corbyn has again outfoxed his opponents. Their strategy could be summed up as “if we make life hell for Jeremy, he will eventually quit” and “if we keep saying he’s useless, party members will eventually realise it”. It’s not working and is unlikely to do so anytime soon.

Watching this week’s Dispatches programme on Channel 4 about the growing influence of Corbyn’s fan club Momentum, I kept thinking that the current leadership challenge was a mistake. Momentum supporters were secretly filmed at the HQ of the Unite union, which provided office space for the “Jeremy for Labour” election campaign but does not support Momentum. Unite is worried that Momentum is open to non-Labour members; indeed, a hard-left activist expelled by Labour was filmed addressing a Momentum meeting.

My abiding impression was that the Corbynistas were given another reason to organise by the fruitless challenge by Owen Smith after the EU referendum. Without that, Momentum wouldn’t have been sitting in Unite’s office hitting the phones to strengthen both Corbyn’s position and their own. The struggle for power inside Labour is a numbers game and the left is much better at it than its opponents. Hopes that Corbyn’s critics would recruit an army of members to outnumber the left fizzled out.

The other lesson from Dispatches is that mainstream Labour will never regain control of the party without the help of the trade unions, a vital force when Neil Kinnock began the painful process of leading Labour back from the electoral wilderness in the 1980s. If big unions are in effect backing Momentum, then the left will remain in the ascendancy.

The contest also allowed Corbyn to stay in his comfort zone, energised by the adulation at rallies bursting at the seams, rather than confront the real world and Labour’s dire standing in the opinion polls. It is a Corbyn camp myth that Labour was on course for general election victory before Labour MPs declared war on Corbyn and divided the party; it was not.

Smith fought hard and decided that man-for-man marking of Corbyn on the left wing was his best hope. But some on the left decided to vote for “the real thing” and others suspected Smith would veer right if he won and so stuck with Corbyn. Smith wasn’t a well-known or big enough figure and won’t be the anti-Corbyn candidate next year. Again with hindsight, Angela Eagle, who was elbowed aside by Smith, might have been a better candidate this year. She might have got under Corbyn’s skin more than Smith did, not least over the nasty social media attacks on women by some Corbynistas.

The critics are unrepentant about their challenge. “If we take all this lying down, the left will just crush us,” said one senior MP who fears he will be deselected by his constituency party.

Corbyn’s MP opponents are divided among themselves about whether to serve in his Shadow Cabinet. Some who resigned this summer believe they must now accept Corbyn’s mandate and unite for the sake of the party. Others would return if the Labour leader allowed his MPs to elect the Shadow Cabinet, a system ditched by Ed Miliband, who took the power to appoint his frontbench team. Corbyn does not want to be a prisoner in a Shadow Cabinet where he is in a minority and so will be tempted to kick the demands for MPs to elect the top team into the very long grass.

When Corbyn became Labour leader a year ago, there were huge tensions between the refuseniks who would not serve in his frontbench team and those who did. Efforts are now under way to prevent a similar split among his critics when some who quit this summer go back. Some plan to serve under Corbyn without being subservient to him – for example, to fight him over every line of policy rather than accept his edicts. That would stretch collective responsibility to breaking point. The returners will inevitably be asked by the media: “Do you think Jeremy Corbyn can and should be prime minister?” If they say yes, they will be asked why they resigned and were among the 172 Labour MPs to declare they had no confidence in the Labour leader – another reason why any sense of unity will be a sham.

The divided ranks of Corbyn’s critics explain why there will not be an SDP-style breakaway in the short term. Although some Labour MPs would walk out now, they lack the critical mass needed to have a chance of success. For now, they will stay and fight, doing battle with Team Corbyn over changes to Labour’s rulebook as both sides try to deploy every weapon.

It reinforces the image of a party looking inwards rather than outwards to the voters it needs to win over. The Corbynistas are much more interested in the internal power struggle. Which leads many mainstream Labour figures to conclude that they have no chance of regaining control of the party until after it has lost another general election. And maybe not even then.