As the Parliamentary Labour Party manages to -- uncharacteristically -- stay out of the headlines for in-fighting, over on the left of Labour trouble is brewing. A bout of civil war has broken out in Momentum, the grassroots group set up to support Jeremy Corbyn's leadership.

The issue? A disagreement over just how democratic the organisation ought to be. The group's head Jon Lansman -- a former Bennite and the brains behind Momentum -- has been accused of behaving in an 'autocratic' manner after he gave his support to a plan to allow every Momentum member to vote on motions on the future of the party, rather than be decided through a delegate system as at present. This has ruffled feathers in the organisation as the meeting of the steering committee -- where it was also decided that the meeting of the national committee should be postponed until December -- was arranged last-minute, meaning some were unable to attend and have a say.

The change to the voting system has been widely interpreted as a means to stop hard left groups exerting too much control on the future direction of the group. By allowing every one of Momentum's 20,000 or so members a vote, some hope to quash the small but effective groups like the Alliance for Workers’ Liberty. However, the decision has been met like a cup of cold sick with certain factions of the group. Since the meeting, the general secretary of the Fire Brigades Union -- Matt Wrack -- has declared a 'major crisis' while another Momentum member has accused Lansman and co of resorting to 'the modus operandi of Blairism during the wilderness years'. Meanwhile, the AWL's Jill Mountford has described the decision as 'bureaucratic manipulation veiled in plebiscitary pseudo-democracy'.

Some of these critics ought to be careful. After all, their calls for a one vote for all system in Labour leadership elections holds less merit if they take a different approach when it works against their interests. As for Lansman's hope to use Momentum to organise national support for Corbyn, this can only happen if the Left refrains from turning on itself.