R (Miller) v Secretary of State for Exiting the European Union

1. Case Title

R (Miller) v Secretary of State for Exiting the European Union

2. Citation

[2017] UKSC 5

3. Court

Supreme Court of the United Kingdom

4. Bench

Lord Neuberger (President), Lady Hale (Deputy President), Lord Mance, Lord Kerr, Lord Clarke, Lord Wilson, Lord Sumption, Lord Hodge, Lord Reed, Lord Carnwath, and Lord Hughes

5. Date of Judgment

24 January 2017

6. Relevant Statutes/Key Provisions

• European Communities Act 1972
  
  
• Article 50 of the Treaty on European Union
  
  
• Referendum Act 2015
  
  
• Royal Prerogative Powers
  
  
• European Union (Notification of Withdrawal) Act 2017

7. Brief Facts

In June 2016, the UK held a public vote called a referendum to decide whether the country should stay in or leave the European Union (EU). Over 17 million people voted to leave, which was about 52% of the voters. This vote was a major event in UK history and became known as Brexit (Britain + Exit).

After the result, the UK Government announced that it would start the legal process of leaving the EU by using Article 50 of the Treaty on European Union. Article 50 is a rule that says how a country can leave the EU. Once Article 50 is triggered, the country has two years to negotiate its exit.

The Government believed it could use its royal prerogative powers to trigger Article 50. These are special powers that the Government can use without asking Parliament, usually for matters like signing treaties with other countries.

However, Gina Miller, a businesswoman and activist, challenged this decision in court. She argued that triggering Article 50 would eventually take away legal rights that people in the UK had under EU law. These rights were part of UK law because of the European Communities Act 1972, which allowed EU laws to be used inside the UK.

Miller said that the Government could not use royal powers to change the law or remove rights—only Parliament could do that. She took the case to the High Court, which agreed with her. The Government then appealed to the Supreme Court, the highest court in the UK, to get the final decision.

8. Issues Involved

This case raised important questions about how the UK Government and Parliament share power:

• Can the Government use its royal prerogative powers to start the process of leaving the EU without asking Parliament?
  The main question was whether the Government had the right to act alone in such an important matter that would change UK law.
  
  
• Does the European Communities Act 1972 require Parliament to be involved before rights from EU law can be removed?
  Since this Act brought EU law into the UK, removing those laws might require Parliament’s approval.
  
  
• Does the result of the 2016 referendum give the Government legal authority to act alone?
  The court needed to decide if the people’s vote was enough to allow the Government to trigger Article 50 without a new law.
  
  
• Do devolved governments (Scotland, Wales, Northern Ireland) need to agree before Article 50 is triggered?
  Some argued that since Brexit would affect the whole UK, devolved governments should have a say.

9. Arguments

Gina Miller’s Side (Petitioner):

• Only Parliament has the power to make or change UK laws. The Government cannot do it alone, even if it is acting on foreign matters.
  
  
• The European Communities Act 1972 allowed EU law to be part of UK law. Because of that Act, people in the UK had rights such as free movement in EU countries, the ability to work or study in the EU, and access to the EU Court of Justice.
  
  
• Triggering Article 50 would begin the process of removing these rights. Since these rights were created by a law passed by Parliament, only Parliament can take them away.
  
  
• The Government should not be allowed to take action that affects people’s legal rights without a vote in Parliament.

Government’s Side (Respondent):

• The Government said that it has royal prerogative powers to sign and cancel international treaties, including the EU treaties.
  
  
• It argued that triggering Article 50 does not remove any rights immediately—it just starts a negotiation process. Parliament could make changes later as needed.
  
  
• The referendum showed what the people wanted, and the Government had a duty to respect that.
  
  
• Parliament already allowed the referendum through the Referendum Act 2015, so the Government believed it already had Parliament’s support.

10. Judgment

The Supreme Court ruled 8–3 in favour of Gina Miller. The majority of the judges agreed that the Government could not trigger Article 50 without Parliament’s approval.

The Court said that triggering Article 50 would lead to big changes in UK law, especially because it would remove EU-related rights that people had under the 1972 Act. These changes were not just international—they would affect people inside the UK.

The judges explained that the royal prerogative cannot be used to change domestic law or take away rights. Only Parliament, which is elected by the people, can make or remove laws in the UK.

The Court also said that the 2016 referendum result was politically important but not legally binding. That’s because the law that created the referendum (the Referendum Act 2015) did not say what the legal consequences of the vote would be. So, the Government could not rely on the vote alone to act.

Lastly, the Court said that Scotland, Wales, and Northern Ireland did not have a legal veto over the decision to leave the EU. The UK Parliament had full control over this matter.

11. Ratio Decidendi

The main legal rule from this case is very clear: The UK Government cannot use royal prerogative powers to remove or change legal rights that were created by Parliament.

If the Government wants to make changes to laws that affect people’s rights, it must first get approval from Parliament by passing a new law.

In simple terms, this case showed that Parliament is the highest law-making body in the UK, and the Government must respect that. The court protected the principle of parliamentary sovereignty, meaning Parliament has the final say in making or changing laws.

12. Obiter Dicta

Some judges also made extra comments that were not part of the main decision but still helpful for understanding the law:

• They said that referendums only have legal force if Parliament clearly says so in law. Since the 2016 referendum law did not say the result was binding, it could not give the Government power to act without Parliament.
  
  
• The judges also explained that Scotland, Wales, and Northern Ireland, even though they are part of the UK, do not have a legal right to stop the UK from leaving the EU. The UK Parliament is responsible for international decisions like this.

These points helped explain the Court’s reasoning and are often used in future cases to support legal arguments, even though they are not binding.

13. Final Decision

The Supreme Court’s final decision was that the UK Government must pass a new law in Parliament before it could trigger Article 50 and start the process of leaving the EU.

Because of this decision, the Government introduced and passed a new law: the European Union (Notification of Withdrawal) Act 2017. This law gave the Prime Minister the legal power to send the Article 50 notice to the EU.

This case is now considered one of the most important constitutional law cases in UK history. It confirmed that:

• Parliament is sovereign and must approve big changes to the law.
  
  
• The Government must follow the law, even when the public has voted in a referendum.
  
  
• The UK’s legal system protects the balance of power between the Government and Parliament.

References (OSCOLA Style)

• R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5
• European Communities Act 1972
• Article 50, Treaty on European Union
• Referendum Act 2015
• European Union (Notification of Withdrawal) Act 2017
• Mark Elliott, ’The Supreme Court’s Judgment in Miller: Brexit, Constitutional Law, and the Limits of Executive Power’ (2017) 76(1) Cambridge Law Journal 1
• Alison Young, ’Triggering Article 50: R (Miller) v Secretary of State for Exiting the European Union’ (2017) 80(3) Modern Law Review 444