This evening, Labour's ruling National Executive Committee has started to discuss a motion which would oust Tom Watson as deputy leader. There is expected to be a vote on this plan, which abolishes the role altogether, tomorrow, and there is a strong chance that it will pass. It was tabled by Momentum founder Jon Lansman, and was narrowly ruled out of order because Watson wasn't present at tonight's meeting. Tomorrow it will be in order.
Why is Labour having this battle on the eve of its autumn conference? It is potentially weeks away from an election, and instead of facing outwards to voters, it is engaged in an internecine battle over internal positions. And not just small roles, but the separately-elected role of the party's deputy leader.
The argument from the Momentum side, though, is that Watson himself is a barrier to the party's election hopes. He is constantly a thorn in the flesh of Jeremy Corbyn's leadership, regularly publicly speaking out against moves by the Left of the party, and someone who, as I revealed recently, is working to see Corbyn leave office. They don't want dissent at this level in the party.
What they won't say, but which is also true, is that ousting Watson will have a devastating effect on morale amongst Corbyn's opponents on the Labour benches. One of the key arguments of the 'stay-and-fight' proponents is that Watson is doing good work to keep the Labour party in a place where it is salvageable. MPs often take public positions on matters after being encouraged to do so by Watson and his acolytes. If he's gone, then what next?
The answer to that question for the 'moderates' might be that the time has come to declare themselves in some way independent of the current Labour party. This is something that has been discussed in the circles around Watson, but up to this point, no-one has really seen a trigger point for it. An NEC vote ousting the deputy leader on the eve of the party conference could spark a row mighty enough to tip the balance.