Chris Williamson, the MP for Derby North, has lost the Labour whip pending an investigation into his conduct after a series of revelations about his conduct. These include that he had said that Labour had been “too apologetic” about the question of antisemitism in the party’s ranks; that he had blasted critics of one party activist suspended for antisemitism as “white privileged”; and that he was planning to host a film screening of the documentary WitchHunt, which champions the cause of Jackie Walker, a Labour activist currently suspended after being accused of allegations of antisemitism.

What does it tell us? Well, the first is that it is a measure of Jeremy Corbyn’s willingness to avoid a total schism within the Labour party and to fight and win the next election. Loyalty is hugely valuable to Corbyn, and an addition to his personal loyalty to Corbyn, Williamson has enthusiastically adopted all of Corbyn’s views and opinions, after a long career in local government in which his political choices were some distance from the orthodox Corbynism he now espouses.

The official line is that Williamson’s suspension is a decision taken in the light of a pattern of behaviour by the Derby North MP. But no-one could, with a straight face, claim that Williamson’s behaviour is a recent discovery. The truth is that Williamson has been repeatedly indulged by the Labour leadership due to his political proximity to Corbyn, and it will have been a very difficult blow for Corbyn personally to remove the whip from him. What matters is that the scale of anger among Labour MPs and activists, coupled with the risk of further defections to the Independent Group, forced the leadership’s hand.

That gives you an idea of the Labour leadership’s commitment to avoiding a further influx of Labour MPs to TIG and Corbyn’s desire to win the next election. It also is an indication of the scale of the change wrought on Labour politics by the emergence of TIG. Had seven MPs not left the Labour party on Monday last week to form a breakaway group, then Williamson would still be a Labour MP now.

It leaves the Labour leadership with two questions. The first, of course, is whether it has acted swiftly enough to avert further exits. The second is whether it will be able to live in the longterm with this new reality, where their position and autonomy is more limited than it has been at any time since the election of 2017.