Indeed. The only practical constraints on parliament are the Laws of Nature, which unlike man's laws cannot be broken, and the will of the People, in defiance of which a Parliament necessarily would fall since the Parliament is constituted from those people.

If Parliament tried to ban booze (as the US Federal Government once did) that's probably not going to go well, and maybe they would (like the US government) be forced to undo that - but all they did here was give away something very few of their citizens likely even knew they had. I was surprised it made headlines.