Labour’s civil war has dramatically reignited after a shock move to abolish Tom Watson’s post as deputy leader of the party.

At a meeting of the National Executive Committee on Friday night, Momentum founder Jon Lansman proposed a motion to scrap the post, citing Watson’s disloyalty over Brexit.

The chair of the NEC ruled the motion out of order before members voted 17  to 10 hear it.

Without a required two thirds majority, the motion was not discussed but it will be on the agenda on Saturday – and is expected to pass.

Among those who voted to hear the abolition motion were the only shadow cabinet ministers present, Diane Abbott and Rebecca Long-Bailey.

Momentum members plus Unite  and other union reps also backed Lansman too.

Watson was absent, having earlier given his apologies because of childcare commitments.

Lansman said that Watson’s call earlier last week for a referendum on Brexit to  take place before a general election, and for the party to campaign for Remain, was proof that he was out of step with the leadership.

The motion will be heard when the NEC meets at 10am on Saturday.

“They’ve got the votes they need,” one NEC source told HuffPost UK. “The Unite-Momentum axis has the numbers.”

“This proves this conference is not about the general election.  It is about cementing control of the party.”

A Momentum source told HuffPost UK: “No one person is more important than beating Boris Johnson, ending austerity and tackling the climate emergency. We just can’t afford to go into an election with a deputy leader set on wrecking Labour’s chances. 

“Labour members overwhelmingly want a deputy leadership election, but our outdated rulebook won’t let it happen. You need 20% of Labour MPs to trigger an election, and they just won’t let the members have a fair and open election.”

The audacious move by Lansman is sure to spark complaints from many Labour MPs on the eve of the party’s annual conference in Brighton.

Normally a motion cannot be brought a second time so quickly as under party standing orders once a motion is voted on it cannot be brought again for three months. 

But Lansman successfully argued that his motion had not been voted on, only a vote to hear it debated.

At the end of the meeting, after discussion with Corbyn’s chief of staff Karie Murphy, he gave notice that he intended to bring the motion back on Saturday and as only a simple majority was required, won that vote.

In what appeared to be a carefully-planned ambush, Lansman had started the meeting by requesting that usual standing orders be suspended to allow discussion of urgent matters.

NEC chair, Unison’s Wendy Nichols, was advised by general secretary Jennie Formby and rulebook official Thomas Gardiner that the orders could be suspended.

In what one source claimed was an attempt to “keep his hands clean of what followed”,  Jeremy Corbyn then left the meeting.

After debate and votes on new selection rules for BAME parliamentary candidates and on the role of ‘acting leader’, Lansman then stunned several present with his new motion.

The motion calls for the deletion of the section on the role of deputy leader and the deletion of all references to the post in the rest of the rulebook.

Nichols ruled the motion out of order as no notice had been given but NEC reps backing Lansman challenged her ruling but failed – by just one vote –  to get the required two-thirds majority needed to do so.

Disputes committee chair Claudia Webbe then arrived and Lansman’s allies attempted to have the vote re-staged, sources said.

But NEC vice-chair Andi Fox argued that as Webbe had not been present at the original vote, she could not take part in a re-run.

At last year’s conference, Watson’s critics tried to push plans for a female-only deputy Labour leader post.

The NEC voted to formally support a radical rule change to establish a second deputy to serve alongside Watson.

But the move was shelved after fears among Jeremy Corbyn’s supporters that it was too soon to install a candidate preferred by the leadership.

Watson had backed the idea, despite suspicions that it had been intended to dilute his own role.

The local constituency party that had tabled the plan decided to withdraw its motion on the floor of the conference, killing off any chance of a vote on it.

A flurry of speculation suggested that Shadow Education Secretary Angela Rayner, Shadow Business Secretary Rebecca Long-Bailey or Shadow Equalities Minister Dawn Butler would all be urged to run for the new post.