Maybe a slightly general commen, but one thing that strikes me is that something like this could end up being the case almost accidentally.
That is, I can see Labour putting a rule like this in place, without really connecting the dots on how it could be used and what the logical outcomes would be.
It would be nice to think that legislators are more careful than that, but it seems pretty clear by now that a lot of laws are being passed because they seem to have the right sentiments, without really properly thinking about the consequences. Or even dismissing the possibilities when they are pointed out.