Brexit: Parliament Must Approve Triggering of Article 50

In the landmark case of R (on the application of Miller and another) (Respondents) v Secretary of State for Exiting the European Union (Appellant) the Supreme Court of the United Kingdom has ruled that the Government  cannot unilaterally trigger Article 50 of the Treaty on the European Union to exit the European Union ("EU".) The decision must be debated before Parliament and legislation must be passed to effect this monumental change to the British legal landscape.

It is important to remember that the purpose of this case was never to challenge the legitimacy of the decision to withdraw from the EU but to confirm whether the authority to commence the process lies solely with the Government or Parliament as a whole.

The process to leave the EU is triggered by enacting Article 50. In taking their appeal to the highest court in the UK, the Government had asserted that its prerogative powers allowed it to engage Article 50 without the need to obtain prior parliamentary consent. The opposing parties contested this, arguing that Parliament must be consulted and the decision must be sanctioned by an Act of Parliament.

The Supreme Court also considered whether such consultation should be extended to the devolved Northern Irish, Scottish and Welsh authorities. This could potentially open a raft of issues if varying responses were received. 

By a majority of 8 to 3, the Court dismissed the Government’s appeal, ruling that an Act of Parliament must be passed to authorise the UK’s departure from the European Union via the enactment of Article 50. The judges were unanimous in their ruling on the cases referred by the Northern Irish, Scottish and Welsh courts, holding that the Government is not legally obliged to consult with the devolved powers. This decision avoids the problematic situation which could have arisen if the devolved powers returned differing responses to the consultation.

The case centres on the interpretation of the European Communities Act 1972 (‘the ECA’) which confirms and establishes the UK’s obligations under EU treaties. Despite the decision of the EU referendum in June 2016, the ECA remains in place and continues to act as an overriding source of domestic law.

The Court ruled that the authority of the ECA can only be removed by an Act of Parliament. Therefore, the ability to trigger Article 50 and withdraw from the EU and the authority of the ECA must rest with Parliament.

The need for prior parliamentary authority was underscored by the fact that withdrawal from the EU would affect existing domestic rights of UK residents. A decision affecting such rights must take the form of duly debated legislation.

The Prime Minister emphasised last week her commitment to a swift Brexit so a Bill giving effect to this judgement is likely to be tabled soon.