Supreme Court – Prorogation Decision

The Supreme Court has come to a decision regarding the question of whether the recent prorogation of Parliament was lawful or unlawful.


This follows the decision during the Joanna Cherry Judicial Review in the Scottish Court of Session held on 3 Sep 2019 which decided that the PM’s advice on prorogation was, as a matter of high policy and political judgement, non-justiciable.

Opinion of Lord Doherty (pdf)

This decision was appealed and the Inner House of the Court of Session ruled that the Prime Minister’s advice to HM the Queen that the United Kingdom Parliament should be prorogued from a day between 9 and 12 September until 14 October was unlawful because it had the purpose of stymying Parliament.

The Government appealed this decision to the Supreme Court.

Details of the decision are available in the document published on 11 September:

Opinion of Lord Carloway, The Lord President in the reclaiming motion by Joanna Cherry QC MP and others (pdf)

and is summarised in my article

Joanna Cherry Judicial Review Appeal

Mention is made in the full written decision that

The prospect of prorogation in the context of the Parliamentary procedures involving the UK’s withdrawal from the EU (commonly called “Brexit”) was first ventilated in the House of Commons as early as March 2019 as a method of circumventing the rule that the withdrawal agreement could not be the subject of a third vote during the same Parliamentary session.

implying that Theresa May’s Withdrawal Agreement with the EU cannot be brought back for further vote in the same Parliamentary session, and can only be voted on again in a new session, following prorogation or dissolution of Parliament.

A separate case, held in the High Court of England and Wales handed down its judgment on the same issue and came to the opposite conclusion.

The High Court heard a challenge to prorogation brought by Gina Miller on 5 September 2019, supported by a number of interveners. The matter was heard by a heavyweight bench, comprising the Lord Chief Justice Lord Burnett, Sir Terence Etherton, Master of the Rolls, and Dame Victoria Sharp, President of the Queen’s Bench Division.

R (Miller) and others v The Prime Minister [2019] EWHC 2381 (QB) (pdf)

We concluded that the decision of the Prime Minister was not justiciable. It is not a matter for the courts

In this case, the claim for judicial review was accordingly dismissed, but with permission granted to appeal directly to the Supreme Court.

Supreme Court Judgement

The Supreme Court heard submissions in both cases with 11 justices sitting over 3 days 19-21 September 2019 and the written judgement was released on 24 September 2019.

The Supreme Court – Case Details

Lady Hale (President), Lord Reed (Deputy President), Lord Kerr, Lord Wilson, Lord Carnwath, Lord Hodge, Lady Black, Lord Lloyd-Jones, Lady Arden, Lord Kitchin and Lord Sales were sitting in this case.

A Summary of the Judgement was published, together with the Full Written Judgement on 24 September 2019. The judgment is the unanimous judgment of all 11 Justices, determines that the PMs advice was unlawful and thus that the prorogation never happened.

Summary Judgement (pdf)

Extracts from the Summary Judgement

The first question is whether the lawfulness of the Prime Minister’s advice to Her Majesty is justiciable. This Court holds that it is.

This Court has concluded that this case is about the limits of the power to advise Her Majesty to prorogue Parliament.

….that the decision to advise Her Majesty to prorogue Parliament was unlawful because it had the effect of frustrating or preventing the ability of Parliament to carry out its constitutional functions without reasonable justification.

and considering remedies

This Court has already concluded that the Prime Minister’s advice to Her Majesty was unlawful, void and of no effect. This means that the Order in Council to which it led was also unlawful, void and of no effect and should be quashed. This means that when the Royal Commissioners walked into the House of Lords it was as if they walked in with a blank sheet of paper. The prorogation was also void and of no effect. Parliament has not been prorogued. This is the unanimous judgment of all 11 Justices.

It is for Parliament, and in particular the Speaker and the Lord Speaker to decide what to do next. Unless there is some Parliamentary rule of which we are unaware, they can take immediate steps to enable each House to meet as soon as possible. It is not clear to us that any step is needed from the Prime Minister, but if it is, the court is pleased that his counsel have told the court that he will take all necessary steps to comply with the terms of any declaration made by this court.

It follows that the Advocate General’s appeal in the case of Cherry is dismissed and Mrs Miller’s appeal is allowed. The same declarations and orders should be made in each case.

The full judgement is available at

Full Written Judgement

Parliament Resumes

Following the decision of the Supreme Court, John Bercow instructed MPs to return to Parliament on Wednesday 25 September 2019.

In the light of that explicit judgment, I have instructed the House authorities to prepare not for the recall – the prorogation was unlawful and is void – to prepare for the resumption of the business of the House of Commons.

Specifically I have instructed the House authorities to undertake such steps as are necessary to ensure that the House of Commons sits tomorrow, that it does so at 11.30am.