Corbynistas now control the Labour Party – but they would be unwise to deselect their critics

The Labour leader should hug his MPs close, not bring in an unnecessary rule change that would be viewed by them as a declaration of war

Labour party leader Jeremy Corbyn listens to NHS staff at Park South Community Centre in Swindon (PA)

Jeremy Corbyn stands at a crossroads. He has a very big decision to make. No, not whether to toughen up Labour’s stance against Brexit. That’s a big call, but can wait until we see the deal Theresa May gets (if she gets one).

Corbyn has a more fundamental decision about Labour’s direction. It will determine the party’s future more than what he does on Brexit. This week a landmark moment was reached when Jon Lansman, founder of the pro-Corbyn group Momentum, and two fellow left-wingers, won election to Labour’s national executive committee (NEC).The left now enjoys unprecedented control of the party – among the 570,000 members, the annual party conference and now its ruling body.

There is one missing piece of the jigsaw – the Parliamentary Labour Party (PLP). Corbyn now has a frontbench team that is fully behind him, not the case when they resigned en masse in 2016. But the Labour backbenches include most of the 80 per cent of his MPs who declared then they had no confidence in him. Today there is a fragile truce. Some former critics have rallied behind Corbyn after his brilliant performance in last June’s election. Others remain Corbyn-sceptics, accept he has earned the right to lead the party into another election but do not believe he will win. A small number of hardline critics dream of another act of defiance, such as declaring a separate “Real Labour PLP” in the hope of mustering a majority among Labour MPs, or even forming a breakaway centre party. But there’s no sign of it happening. “There’s still a civil war, it’s just gone underground,” one Corbyn ally told me. A prominent Corbyn-sceptic agreed, saying: “We have to bide our time, and let him fail.”

Given such unrepentant views, at one level we could hardly blame Corbyn supporters for seizing their moment of ultimate power and, to borrow a phrase from the Daily Mail on Brexit, wanting to “crush the saboteurs”. Some want to ensure the PLP reflects the party membership more fully by making it easier to oust Labour MPs before the next general election. Paul Mason, the Corbynista journalist, reacted to the NEC election results by tweeting: “Now let’s have mandatory selections of all MP candidates".

John McDonnell, the Shadow Chancellor and second most powerful person in Labour, might share Mason’s instincts. He urged Corbyn not to restore former critics he regards as traitors back to the frontbench after last year’s election; as usual, Corbyn agreed.

This week’s immediate removal of Ann Black, a highly respected left-winger on the NEC, as chairman of Labour’s internal disputes sub-committee, in favour of Momentum’s even more left-wing Christine Shawcroft, is very symbolic. It suggests the Corbynistas will use all the levers now at their disposal.

Mandatory reselection was pushed through by the left in 1980 during its previous heyday when its standard-bearer was Tony Benn, whose acolytes included Corbyn and Lansman. But the anti-left forces were stronger than they are today and fought back. Automatic reselection was ended under Neil Kinnock’s leadership in 1990.

There have been mixed signals from Team Corbyn about whether to bring it back. Officially there are “no plans.” But a review of the rulebook by Katy Clark, Corbyn’s political secretary, is underway. Today Corbyn hinted that it might result in changes, telling The Guardian that Labour “will look at democracy within the party and look at the process of selections. We should all be accountable all the time.”

Corbyn should resist temptation and tell his enthusiastic supporters not to purge Labour MPs for not being pure enough. If an MP, whether right or left, is underperforming, the existing system of “trigger ballots” can be used by local members to force a reselection contest.

The Labour leader should hug his MP critics close, not bring in an unnecessary rule change that would be viewed by them as a declaration of war. If MPs were deselected, they might resign and force tricky by-elections, or form a breakaway group in Parliament. They wouldn't threaten Corbyn’s ascendancy in the party, but the public would take note, and they could damage his prospects in the country.

The Tories, struggling with their own internal tensions over Brexit, would love nothing more than Labour to relapse into the internecine strife of the 1980s. All Labour’s factions should remember what unites them – like this week’s effective party political broadcast on the NHS. Most Corbyn critics now recognise the popularity of last June’s manifesto. He has been proved right on public-private partnerships by Carillion’s collapse. If any sceptics doubted Corbyn’s desire to become prime minister, his sacking of his soulmate Chris Williamson from the frontbench shows they were wrong.

All parties are coalitions; Labour’s factions need each other. Even if the truce is fragile, it will need to hold for the party to regain power. That will not happen if it is in a state of open civil war.