As Maya says, this will be interesting. This is going to put Labour firmly on the spot. How will they react? I suspect that Steph will regret his actions much in the same way that the GLP's lawsuits and appeals generally end up solidifying our position in law.
At the very least, this will force Labour to stop trying to plsy both sides at the same time. They'll have to decidd if they're going to stand fully behind the law or not.