Case study Miller v Sec of State for Exiting the EU 2016


R (Miller) v Secretary of State for Exiting the European Union (2016)

This case was heard originally in the High Court, Queen’s Bench Division, in October 2016 and was brought to appeal in the Supreme Court later in the same year. It is possibly the most important constitutional case to appear in the courts in recent history and illustrates well the relationship between the judiciary and government, as well as the relationship between Parliament and government.

Gina Miller, a private citizen, requested a judicial review of whether the Secretary of State for Exiting the European Union (David Davis) had the prerogative power to trigger Article 50 of the EU which would start the process of the UK’s departure. Her legal argument was that Parliament is sovereign and this stands above the claimed prerogative power to bring the UK out of the EU. The government’s position was that it did have such a prerogative power.

The High Court ruled that the government did not have such a prerogative power and that the sovereignty of Parliament had to be exercised in this case. This was because departure from the EU would affect the rights of UK citizens in some cases.



This ruling was later upheld in the Supreme Court. It forced the government to seek parliamentary approval to trigger Article 50 and begin the process of leaving the EU. Two extracts from the High Court’s judgement are especially signifcant:

The courts have a constitutional duty fundamental to the rule of law in the same way as the courts enforce other laws.

and: We hold the Secretary of State does not have the power under the Crown’s prerogative [i.e. the royal prerogative] to give notice pursuant to Article 50 of the Treaty of the European Union for the UK to withdraw from the European Union.

The High Court decision was emphatically confirmed by the Supreme Court in January 2017.

The Miller case illustrates a number of constitutional realities:

● That it is for the judiciary to determine the limits of the government’s prerogative powers

● That the rule of law is superior to political considerations

● That Parliament is sovereign over such matters in that the decision to leave the EU affects the rights of EU citizens and so the government must obtain parliamentary approval

● That referendums are not legally binding and their outcome must be confirmed by Parliament, not government

Following the case, several newspapers proclaimed that the judiciary was attempting to defy the will of the people, but politicians of all parties rushed to defend the judiciary, arguing that its independence from such pressures must be resisted.