Parliament can make or unmake any law, and no court can set an Act aside — the doctrine on which the whole UK constitution rests.
Almost every question in public law eventually runs into this doctrine, so the way its pieces fit together matters as much as the headline rule. This chapter starts with the three limbs of sovereignty and Parliament's relationship with the courts, then places Acts of Parliament above the common law, the prerogative, international treaties and delegated legislation, before turning to what makes a valid Act — including the enrolled bill rule and how a Bill can pass without the Lords. It then examines whether Parliament can bind its successors, implied repeal and the special status of constitutional statutes, and the careful accommodations struck with the Human Rights Act 1998 and devolution. Finally it covers how the courts guard fundamental rights through the principle of legality and their treatment of ouster and Henry VIII clauses, the scope of parliamentary privilege, the fate of EU law after Brexit, and whether any genuine limits on sovereignty remain.
