Who May Change the Law?

The dispute

Following the EU referendum, the Government proposed to give notice under Article 50 using prerogative powers over international affairs. The English proceedings, heard alongside Northern Irish references, challenged its authority to act without legislation.

The court’s reasoning

The majority held that an Act of Parliament was required. Withdrawal would remove domestic rights and cut off a source of domestic law established through the European Communities Act 1972. Ministers could not achieve that change through prerogative power alone. The referendum legislation had not itself supplied the necessary authority. Lord Reed's dissent took a different view of the 1972 Act: its operation depended on treaty membership without removing the executive's power over that membership. The Court was not deciding whether Brexit was desirable.

Supreme Court case page, judgment and official summary. Majority reasoning at paragraphs 60–95 and 116–124; Lord Reed's dissent begins at paragraph 153.

Personal reflection

What interests me is the discipline required to keep political preference separate from institutional competence. It is easy to value procedure when it protects an outcome we favour and dismiss it when it delays one. A constitutional principle becomes meaningful only when it can survive that change in our sympathies.

The dissent deserves serious attention. Disagreement concerned the legal architecture through which international commitments affected domestic rights, not whether rights mattered. Reading both approaches makes the decision more intellectually useful than a story in which judges simply defeated or defended a political project.

I take the larger lesson to concern borrowed authority. A government may possess a mandate to pursue a policy while still needing the particular legal powers required to implement it. Insisting on that distinction is a way of making responsibility traceable. The people who decide should have to act through the institution legally entrusted with the decision.

Reading the decision

Supreme Court case page, judgment and official summary. Majority reasoning at paragraphs 60–95 and 116–124; Lord Reed's dissent begins at paragraph 153.

These are historical readings of the named judgments, with separate personal commentary. They do not survey every later decision or legislative change and are not advice for an individual case.

The cited sources distinguish the judgment from any official press summary; the judgment is the authoritative account.