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The UK Supreme Court’s decision on the prorogation cases

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Posted by Iain Colville on 24 September 2019

Iain Colville Partner

Today’s unanimous judgment from the 11 Supreme Court justices in the combined Miller/Cherry appeals has rightly hit the headlines.

In upholding the long-established constitutional role of Parliament in scrutinising the government’s exercise of its powers, the Court has ruled that the Prime Minister’s advice to the Queen in late August 2019 to prorogue the UK Parliament was unlawful. As a consequence, Parliament is not currently prorogued.

The political ramifications of this important legal decision remain to be seen. However, the Supreme Court’s judgment is carefully worded and well argued, and is certainly worth reading in full. 

What was all the fuss about?

As the justices emphasise, this case was not dealing with the issue of when or on what terms the UK is to leave the European Union. Indeed, the lawyers for the government argued consistently that the decision to prorogue Parliament had nothing to do with Brexit.

Rather, the case concerned only whether the advice given by the Prime Minister (to the Queen) that Parliament should be prorogued from mid-September until 14 October, was lawful and the legal consequences if it was not.

The power to prorogue Parliament is one of the ancient prerogative powers, today exercised by the Queen upon advice from the Prime Minister of the day. The first issue was whether this particular prerogative power was even capable of being considered or reviewed by the courts.

Who argued what?

This decision was an appeal from 2 separate cases, raising overlapping issues, one from the English High Court and the other from the Inner House of the Court of Session in Scotland.

In the English case (Miller v The Prime Minister), the High Court decided that the question of the lawfulness of the Prime Minister’s advice on prorogation was not justiciable, or not capable of review by the courts.  Mrs Miller appealed to the Supreme Court, arguing that the advice should be justiciable, and that the advice was unlawful.

The Scottish case (Cherry & others v the Advocate General) was brought by a cross party group of 75 MPs and Peers on similar grounds against the UK Government’s legal representative in Scotland. Initially the Scottish case was decided with the same outcome as the English case, but this was appealed to a more senior court in Scotland, the Inner House of the Court of Session, who decided that the Prime Minister’s advice on prorogation was justiciable, was indeed unlawful and the Prime Minister had misled the Queen as to the reason for proroguing Parliament. 

The Court also heard arguments from a number of other parties (known as intervenors) including the Lord Advocate (the legal representative of the Scottish devolved government), Raymond McCord (who brought a similar case against the government in the Northern Irish courts), the Counsel General for Wales (the legal representative of the Welsh devolved government) and Sir John Major as well as written submissions from Baroness Chakrabarti (the Shadow Attorney General) and the Public Law Project.

What has been decided?

In brief, the Court reached the following conclusions:

  1. The question of whether the prime minister’s advice to the Queen was lawful is justiciable in a court of law. The Court found the basis for this in the longstanding rule (dating back to the 17th century), by which the government has no powers other than those that the law allows (see paragraphs 28 to 37 and 52).

  2. If a decision to prorogue has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions as a legislature and as the body responsible for the supervision of the executive, then the advice to prorogue would be unlawful. The rationale for this is the sovereignty of Parliament and its important role in holding the government of the day accountable (see paragraphs 38 to 51).

  3. The Prime Minister’s advice to the Queen in relation to this prorogation undoubtedly has the effect of frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions and upon the evidence before the Court, there was no reason (let alone a good reason) to advise the prorogation for 5 weeks (see paragraphs 55 to 61).

  4. The Court therefore declared that the advice was unlawful. The Court went further and also decided that if the advice was unlawful, the prorogation itself was unlawful, of no effect and so was void. Parliament was not prorogued and the Court decided that it was therefore for the Speaker and Lord Speaker to convene Parliament (see paragraphs 62 to 70).

Given the Court’s conclusion about the unlawfulness of the Prime Minister’s advice, it was not necessary to consider the Prime Minister’s motive in giving his advice to the Queen, thus elegantly side-stepping the politically sensitive question of the Prime Minister’s motive and purpose in seeking prorogation (see paragraphs 53 and 54).

Who or what has made this decision?

These matters were decided by the UK Supreme Court, which is the highest court in the UK and the only court in the UK that can deal with all three legal jurisdictions (England & Wales, Scotland and Northern Ireland). 

The Supreme Court was created on 1 October 2009 and replaced the judicial function of the House of Lords as the UK’s final court of appeal for all UK civil cases and criminal cases from England, Wales and Northern Ireland. The Court is based in the former Middlesex Guildhall, opposite the Houses of Parliament and Westminster Abbey in London.

There are 12 justices or judges in the UK Supreme Court. The Court always sits with an odd number of judges to ensure the result is not tied. Usually it sits with panels of 5, 7 or, in the most important cases, 9 justices. However, because of the significance of the issues and for only the second time ever, a panel of 11 justices heard this case including judges from England, Scotland, Northern Ireland and Wales.

Today’s judgment was the unanimous conclusion of all 11 judges.

Can there be a further appeal?

No, there can be no appeal from a decision of the UK Supreme Court.

What about an appeal to the European Court of Justice?

There is no basis upon which decisions of the UK Supreme Court can be appealed to the Court of Justice of the EU.

It is correct that the Court of Justice does deal with particular questions referred to it by a national court (such as the UK Supreme Court or any other UK court) but such a reference is only made where the national court decides that a case before it concerns a question of EU law which is uncertain or ambiguous. 

However, no issues of EU law arose in these cases and the UK Supreme Court did not refer any questions of EU law to the Court of Justice in this instance.

Where can I find out more?

The full judgment and a summary are published on the UK Supreme Court website.

In addition, the written submissions of each party, video recordings of the hearings last week and a video of the handing down today are also available on the Court’s website.

About the author


About the author

Iain is an experienced dispute resolution lawyer, who specialises in disputes involving innovation and technology.

Iain Colville

Iain is an experienced dispute resolution lawyer, who specialises in disputes involving innovation and technology.

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