A constitution is just a piece of paper. It only has meaning because people respect it. Passing a law you know violates a constitution is a direct attack on the rule of law itself, and should probably come with penalties attached. Certainly, the fact that politicians in the USA very regularly and blatantly pass laws they know will be struck down by the courts a few years later is one of the stronger arguments I've seen for why the UK shouldn't bother with setting up a written constitution. It's got no teeth. Governments can simply pass and enforce illegal laws, exploiting the lack of speed and capacity in the court system. Then when one gets struck down, just pass another in a similar way.