Limitedsimba123,
Well, this is not quite constitutional law as I was taught it. I would say that the main function of Parliament is to pass statute law and grant taxes etc. It is the role of Her Majesty's Loyal Opposition - ie, within Parliament - to challenge and examine the work of the government. After all, if the government can't command parliamentary support, it can't function. That when one has an election, which would be the normal course in the present situation. The opposition are playing politics with this principle, probably because they know they'll lose the election.
I think you may be over-interpreting my position somewhat. I don't think the Supreme Court judgment is something out of leftfield. However I think it's very easy to see why a good many senior lawyers (including the Attorney-General) got wrongfooted by the SC adding to the traditional principle (that prerogatives can't frustrate statute law) by saying that a prerogative also can't be used if the effect is to prevent parliamentary scrutiny without reasonable justification. It looks a little like statute-by-judge, to be honest.
And - ChazsBrilliantAttitude - that brings me to a concern I have about the judgment. The UK constitution actually doesn't have a strong separation of powers at all as in theory Parliament can do what it likes. Parliament has already passed an Act requiring BoJo the Clown to seek an extension and accept one if offered. There was an attempt to pass legislation allowing Parliament to command the government to negotiate one way or another simply by passing resolutions. In my view that's back-seat driving by Parliament, ie a big transgression into the government's domain and one that would cause a lot of squabbles (and make some lawyers very rich) if the UK had a written, codified constitution with a formal separation of powers. What the SC has done is give the green light to Parliament doing more of the same and I think that may be a mistake in the long run.
It's good to see Bojo get a kick in the pants, but I suspect that this judgment won't date well. Perhaps it'll get adopted in the other common-law jurisdictions but I suspect it'll be politely referred to and otherwise ignored.
I have to add that I think bojo behaved appallingly yesterday. However, a whole lot of people need to watch their language, and the lawyer who referred to him as the "father of lies" shouldn't have been allowed to get away with that in court.