Miller & Anor, R (On the Application Of) v The Secretary of State for Exiting the European Union (Rev 1)

The Crown cannot use prerogative powers to give notice under Article 50 where that notice will alter domestic law or remove statutory rights. The European Communities Act 1972 gave EU law effect in domestic law and created rights whose continuation could not be left to executive choice. Constitutional principles, including Parliamentary sovereignty and the rule that prerogative powers cannot alter domestic law, informed the interpretation of that Act. The European Union Referendum Act 2015 authorised an advisory referendum only; it did not confer power to give Article 50 notice. Parliamentary authorisation was therefore required.

The claimants sought judicial review of the Secretary of State’s proposed use of the Crown’s prerogative to notify the European Council under Article 50 TEU of the United Kingdom’s intention to withdraw from the European Union. The referendum held under the European Union Referendum Act 2015 had resulted in a vote to leave. The parties agreed that the issue was justiciable.

The central question was whether the executive could give notice under Article 50 without prior primary legislation, given the effect of withdrawal on rights and obligations made enforceable in domestic law by the European Communities Act 1972.

1. Article 50 and domestic consequences. Article 50 notice was irrevocable and could not be conditional. Giving notice would inevitably lead, subject to an agreed extension or earlier withdrawal agreement, to the Treaties ceasing to apply. It would therefore have direct effects on domestic rights and law.
2. Constitutional principles. Parliament is sovereign and primary legislation is supreme. The Crown’s prerogative powers are limited by the common law and cannot be used to alter domestic law or remove rights conferred by statute. The prerogative power to conduct international relations exists on the international plane and does not ordinarily authorise changes to domestic law.
3. Construction of the 1972 Act. The European Communities Act 1972 was a constitutional statute. Sections 2(1), 2(2) and 3(1), read in their constitutional context, showed that Parliament intended EU rights, remedies, obligations and procedures to have domestic effect. It did not intend those legal effects to be capable of being removed by unilateral executive action. The Act therefore impliedly removed any prerogative power to withdraw from the Treaties in a way that would strip its provisions of effect.
4. Rights affected. The conclusion applied both to EU rights capable of replication in domestic law and to rights enjoyed by British citizens in other Member States. Rights which could not be replicated in domestic law would also be lost on withdrawal. The possibility of later legislation preserving some rights did not authorise the executive to pre-empt Parliament.
5. Authorities. Attorney General v De Keyser’s Royal Hotel and R v Secretary of State for the Home Department, ex p Fire Brigades Union confirmed that prerogative powers may be impliedly abrogated by statute. R v Secretary of State for Foreign and Commonwealth Affairs, ex p Rees-Mogg was confined to a case where treaty ratification would not alter domestic law.
6. Referendum. The 2015 Act contained no clear language authorising the Crown to give Article 50 notice. The referendum was constitutionally advisory and did not itself supply statutory authority.
7. Disposition. Permission to seek judicial review was granted. The court held that the Secretary of State had no power under the Crown’s prerogative to give Article 50 notice. Declaratory relief was appropriate, with its precise form to be addressed after the judgment.

First instance judicial review proceedings. No prior appellate decision is stated in the judgment.