Crossbench
UK PoliticsOverviewDemocracy and participationPolitical partiesElectoral systemsVoting behaviour and the media
UK GovernmentOverviewThe constitutionParliamentPrime Minister and executiveRelations between the branches
Political IdeasOverviewLiberalismConservatismSocialismFeminismComparison framework
Global PoliticsOverviewComparative theoriesThe state and globalisationPower and developmentsRegionalism and the EUGlobal governance: political and economicGlobal governance: human rights and environmental
Current AffairsPower MapVoter ProfileParty IndexGlossaryExam Support Site Policies
ApprovedCurrentCase
Title

Supreme Court rules the 2019 prorogation of Parliament unlawful

Date
24 September 2019 (judgment)

What happened?

In late August 2019 the Prime Minister, Boris Johnson, advised the Queen to prorogue, or suspend, Parliament for several weeks in the period before the UK’s scheduled departure from the EU. Critics argued that the effect would be to limit parliamentary scrutiny at a crucial moment.

Gina Miller in England and a group of parliamentarians in Scotland challenged the advice in the courts. The Supreme Court heard the two cases together and gave judgment on 24 September 2019.

Relevant factual details

  • VerifiedJudgment given on 24 September 2019: [2019] UKSC 41.
  • VerifiedA unanimous decision of all 11 Justices, the maximum number permitted to sit.
  • VerifiedThe Court held that the lawfulness of the advice to prorogue was a question the courts could decide.
  • VerifiedTest applied: a prorogation is unlawful if it frustrates or prevents, without reasonable justification, Parliament’s ability to carry out its constitutional functions.
  • VerifiedThe advice was unlawful, void and of no effect; the Order in Council was quashed, so Parliament had not been prorogued.
  • Source to checkThe Dissolution and Calling of Parliament Act 2022 later provided that the courts may not question the revived power to dissolve Parliament.

Verified Confirmed against an original or authoritative source
Reported Taken from a secondary or reference source; to be confirmed against the original
Source to check Established knowledge, but the cited source has not yet been opened

Why is it politically significant?

The judgment showed the Supreme Court setting legal limits on a prerogative power to protect Parliament’s role. It remains the leading example in debates about the political role of the judiciary and about relations between the executive, Parliament and the courts.

Arguments and counterarguments

Which arguments does it support?

The Supreme Court is an effective check on the executive

Reasoning
Courts can enforce legal limits on how ministers use their powers.
Evidence
A unanimous ruling that the Prime Minister’s advice was unlawful and of no effect.
How it supports the argument
The Court reversed a decision of the Prime Minister, and the prorogation was treated as never having happened.

Parliament remains sovereign

Reasoning
Courts can uphold parliamentary sovereignty rather than compete with it.
Evidence
The Court’s test turned on whether prorogation frustrated Parliament’s constitutional functions.
How it supports the argument
The judgment protected Parliament against the executive rather than placing the courts above Parliament.

Which counterarguments exist?

Alternative view

The Court entered political territory

Critics argued that prorogation had previously been treated as a political matter beyond the courts’ reach, so the ruling expanded judicial power.

Other explanations

Parliament can limit the courts’ reach

Parliament later legislated so that the courts cannot question the revived power to dissolve Parliament, showing that the political branches can respond to judicial rulings.

Limits of the evidence

An unusual case

The judgment concerned exceptional circumstances; it does not show that the courts routinely constrain the executive.

Concepts and connections

Sources and verification

Event24 September 2019 (judgment)
Added to bank4 November 2026
Last checked4 November 2026
Next check due4 May 2027
  1. 1
    Publisher The National Archives, Find Case LawPublished 24 September 2019Type Court judgmentChecked 4 November 2026
    Opened
  2. 3
    Publisher The Supreme CourtPublished not statedType Court recordChecked not yet opened
    Source to check
  3. 2
    Publisher legislation.gov.ukPublished not statedType LegislationChecked 4 November 2026
    Opened

About this example

Is it still current?

Current

The facts and their significance still stand.

Why it is in the bank

The leading modern case on the courts, the executive and Parliament.

  • ✓Relevance to the specification
  • ✓Strength and reliability of the evidence
  • ✓Importance to a wider political debate
  • ✓Usefulness in evaluative essays
  • ✓Connections to other topics
  • PartlySufficiently currentFrom 2019, but still the leading case on the subject.
  • ✓Adds something new to the bank

Editorial status

Approved

Signed off for students.

Origin: AI draft (Claude) · Reviewer: Editor

Every fact on this page has been checked against original sources.