Whenever the Labour left has the temerity to push for the changes it wants to see within the party, it unleashes what Gregory Elliott once derisively called the “Burkean Furies.” Such is the nervousness surrounding the impending reselection of Labour MPs, it only takes a single Labour member to send an (albeit ill-considered) email to their CLP chair for the indignant wrath of the deputy leader to be splashed across the national press.

The Labour left was unsuccessful in its efforts to secure full mandatory reselection, or “open selection,” at last year’s party conference — but it did manage to significantly lower the threshold of the trigger ballot system. Under the reformed system, it only takes one-third of branch parties to vote in favor of reselection for a process to take place. Some reports suggest (though their reliability is difficult to gauge) that as many as seventy MPs, including some of those on the Left, could find themselves vulnerable under this new setup.

In the weeks and months ahead, Labour left activists should expect to face a fierce and bitter rearguard action from the party’s right wing, and its associates in the press, against their efforts to reshape the Parliamentary Labour Party (PLP). But we cannot allow ourselves to be browbeaten into docility: unless there are substantial changes to the political composition of the PLP at the next general election, any left-led Labour government will be severely hamstrung from the outset, and will stand only a remote chance of successfully carrying out its program. The forthcoming round of trigger ballots therefore represents a significant milestone in the long struggle to renew the Labour Party.