GMB general secretary Paul Kenny chose to feign innocence when he arrived at Portcullis House for his meeting with Ed Miliband earlier today, the day after his union announced  that it was cutting its affiliation fees to Labour from £1.2m to £150,000. "What's all the fuss over? All we're doing, if you like, is going towards what Ed says he wants," he remarked .
But as Kenny knows, the objection is that he has pre-emptively disaffiliated 88% of the union's political levy-payers from Labour, rather than trying to persuade more to sign up once an opt-in system is introduced. It was an unambiguous vote of no confidence in Miliband's reforms.
In its statement yesterday, the GMB, the third-largest union, also warned of "further reductions in spending on Labour party campaigns and initiatives". For Labour, which relies on large one-off donations from the unions to fund its general election campaigns, it was an ominous threat.
Privately, however, some in the party are more sanguine. They regard Kenny's move as a negotiating tactic designed to deter Miliband from reducing the unions' voting power in leadership elections and at party conferences. The GMB is not due to implement the funding cut until January, leaving Miliband wtih time to reach an agreement. But the dilemma is already becoming clear: does Miliband pursue comprehensive change and risk losing even more funding, or does he compromise and risk being accused of bottling reform?