[frereubu]

They can't do that because it would make a mockery of the legal system. Parliament does outrank the Supreme Court, but they do that by passing legislation, not just having a vote and going "no, sorry, lol". The whole legal system is built on precedent, which is incompatible with parliament overriding it piecemeal.

[iamnothere]

Technically, according to the framework under which it governs itself, Parliament could pass almost any bill, including things like bills of attainder that are panned globally as violating basic freedoms (for good reason). It just “chooses not to” (or rather is restrained by increasingly lax public oversight).