Authored By: Parmis
Bales College
Case Citation and Basic Information
Case Name: R (Miller) v The Prime Minister and Cherry v Advocate General for Scotland
Citation: [2019] UKSC 41
Court: UK Supreme Court
Date of Judgment: 24 September 2019
Judges: Lady Hale (President), Lord Reed (Deputy President), Lord Kerr, Lord Wilson, Lord Carnwath, Lord Hodge, Lady Black, Lord Lloyd-Jones, Lord Kitchin, Lord Sales and Lord Briggs.
Introduction
The ruling in R (Miller) v The Prime Minister and Cherry v Advocate General for Scotland [2019] UKSC 41 is considered one of the most important constitutional cases in recent British legal history. Issued in the context of political uncertainty during the United Kingdom’s exit from the European Union, the case examined whether the Prime Minister’s recommendation to suspend Parliament for five weeks was legitimate. The Supreme Court had to assess the boundaries of executive authority, the judiciary’s role in reviewing prerogative powers, and the foundational constitutional principles of the UK’s unwritten constitution. The case emerged following Prime Minister Boris Johnson’s advice to Queen Elizabeth II to suspend Parliament from 9 September to 14 October 2019. This unusually long suspension took place during a crucial time leading up to the intended Brexit date of 31 October 2019. Opponents claimed that this move hindered Parliament from examining the Government’s Brexit plans and ensuring ministerial accountability.
The Supreme Court unanimously found that the recommendation to suspend Parliament was unlawful as it effectively obstructed Parliament’s constitutional duties without adequate reasoning. Consequently, the suspension was deemed null and void, indicating that Parliament had not been legally suspended. The judgment reinforced the constitutional principles of parliamentary sovereignty, accountability, and the rule of law, while clarifying that executive prerogative powers are open to judicial review when they pose a threat to these principles.
Facts of the Case
After the 2016 referendum, where the majority voted for the UK to exit the European Union, Parliament faced significant disagreement regarding the Brexit terms. By mid-2019, political tensions had escalated following Boris Johnson’s assumption of the role of Prime Minister in July 2019. Johnson committed to ensuring the UK would leave the EU by 31 October 2019, with or without a withdrawal agreement in place. On 28 August 2019, the Prime Minister advised Queen Elizabeth II to prorogue Parliament from early September until 14 October.
Although prorogation is an established constitutional process used to conclude a parliamentary session ahead of a new King’s or Queen’s Speech, the suggested suspension of around five weeks was notably longer than usual. This meant Parliament could not discuss Brexit policy, challenge ministers, or enact legislation during a critically important political period. The decision quickly led to legal challenges in various UK jurisdictions. In England and Wales, Gina Miller, a businesswoman and activist, sought a judicial review, arguing that the prorogation aimed to suppress Parliament, making it unconstitutional.
The High Court dismissed her claim, stating the matter was political rather than legal and thus not subject to judicial review. Simultaneously, in Scotland, Joanna Cherry QC MP and other parliamentarians initiated a separate legal action. Unlike the English High Court, the Inner House of the Court of Session determined that the Prime Minister’s counsel was intended to obstruct parliamentary oversight, rendering the prorogation unlawful. Due to the differing decisions of the two courts, the appeals were consolidated and presented to the UK Supreme Court. The Court was tasked with deciding whether the prorogation’s legality could be judicially reviewed and, if so, whether the Prime Minister’s counsel was lawful.
Legal Issues
The Supreme Court examined several key constitutional questions. The initial issue was justiciability: the Court needed to determine if the use of the royal prerogative concerning prorogation was appropriate for judicial assessment or whether it was solely within the political realm. Historically, some prerogative powers have been considered unsuitable for judicial review because they involve political judgment rather than legal criteria. If the issue was deemed justiciable, the next step for the Court was to decide on the legal boundaries of the Prime Minister’s authority to advise the monarch to prorogue Parliament, specifically considering if constitutional principles could limit this executive authority.
Additionally, the Court evaluated whether the advice given to the Queen unlawfully obstructed or hindered Parliament from performing its constitutional roles, such as legislation, executive oversight, and ministerial accountability. Finally, if the advice was determined to be unlawful, the Court had to establish the legal implications, deciding whether the prorogation was legally valid or should be regarded as having no legal effect.
5.1 Petitioners’ Arguments
Gina Miller and Joanna Cherry MP, the claimants, contended that the Prime Minister misused the royal prerogative by recommending that the Queen suspend Parliament for an unusually extended period during a crucial political juncture in recent constitutional history. They asserted that the underlying motive for this suspension was to obstruct Parliament from examining the Government’s Brexit strategy and evade parliamentary responsibility. The petitioners grounded their case on two core constitutional doctrines: parliamentary sovereignty and parliamentary accountability.
Parliamentary sovereignty dictates that Parliament remains the ultimate legislative authority in the United Kingdom, while parliamentary accountability requires that ministers are accountable to Parliament for their use of executive power. By suspending Parliament for more than five weeks, the Government substantially undermined both principles. Additionally, the petitioners posited that although the royal prerogative permits prorogation, these prerogative powers are not boundless.
Previous constitutional precedents, such as the Case of Proclamations (1611) and the initial Miller case regarding Article 50, affirmed that prerogative powers are legally constrained and cannot supersede constitutional principles set by Parliament. Therefore, the petitioners argued that the courts had the authority to review the legality of the Prime Minister’s advice and should pronounce the prorogation unlawful.
5.2 Respondent’s Arguments
The Government maintained that prorogation is fundamentally a political issue that pertains to the constitutional dynamics between the Prime Minister and the Monarch. As a result, it asserted that the matter was not subject to judicial review because there were no legal standards available to evaluate this exercise of prerogative power.
The Government also argued that determining the suitable duration of prorogation required political judgment rather than legal scrutiny. It claimed that Parliament was still able to fulfill its constitutional duties both before and after the prorogation and that the suspension simply enabled the Government to develop a new legislative agenda for the upcoming Queen’s Speech.
Furthermore, the Government argued that judicial involvement would violate the constitutional principle of the separation of powers by permitting the judiciary to intrude upon political decisions that rightfully belonged to the executive branch.
Court’s Reasoning and Analysis
The Supreme Court unanimously dismissed the Government’s arguments. Lady Hale, delivering the Court’s decision, highlighted that even though prorogation is conducted under the royal prerogative, possessing such a prerogative does not exempt it from judicial review. The Court made a distinction between assessing the political value of a decision and evaluating whether the executive had overstepped its legal boundaries.
The Court asserted that the constitutional doctrines of parliamentary sovereignty and accountability set clear legal benchmarks for evaluating the exercise of the prerogative. Parliament cannot fulfill its constitutional duties if it is unlawfully prevented from convening.
The Supreme Court established a significant legal criterion: proroguing Parliament is illegal if it effectively frustrates or obstructs Parliament from fulfilling its constitutional roles without reasonable justification. Using this criterion, the Court determined that the five-week prorogation took place during a crucial constitutional period right before the expected Brexit deadline, preventing Parliament from debating laws, scrutinizing ministers, and questioning Government policies when these activities were particularly crucial.
The Government failed to provide satisfactory evidence justifying the necessity of such an extended prorogation. Although preparing for a Queen’s Speech was deemed a valid governmental aim, the Court found that this could have been accomplished with a much shorter suspension.
Significantly, the Court clarified that it was not evaluating the desirability of Brexit or the appropriateness of the Government’s political goals but rather whether the executive acted within the constitutional boundaries defined by law.
Judgment and Ratio Decidendi
The Supreme Court unanimously held that the Prime Minister’s advice to Her Majesty the Queen was unlawful because it had the effect of frustrating Parliament’s constitutional functions without reasonable justification.
Since the advice itself was unlawful, the Order in Council authorising the prorogation was likewise unlawful and void. Consequently, the prorogation had no legal effect. In constitutional terms, Parliament had never been prorogued.
The Speakers of both Houses of Parliament were therefore able to reconvene Parliament immediately without requiring a fresh summons from the Monarch.
The ratio decidendi established by the Court can be summarised as follows:
The exercise of the royal prerogative to prorogue Parliament is subject to judicial review. Where a prorogation has the effect of frustrating or preventing Parliament from carrying out its constitutional functions without reasonable justification, the advice to prorogue is unlawful and any resulting prorogation is null and void.
This principle represents one of the clearest judicial statements that executive prerogative powers remain constrained by constitutional principles and are reviewable by the courts where necessary to protect the rule of law.
8.1 Significance of the Decision
The decision is widely regarded as one of the most important constitutional judgments delivered by the UK Supreme Court. It reinforced the constitutional doctrine that no public authority, including the Prime Minister, is above the law. By confirming that prerogative powers are reviewable where they threaten constitutional principles, the Court strengthened the rule of law within the UK’s uncodified constitution.
The judgment also reaffirmed parliamentary sovereignty. Parliament cannot legislate or scrutinise the executive if it is prevented from sitting for an unjustified period. The decision therefore protects Parliament from executive attempts to avoid political accountability.
Furthermore, the case clarified the constitutional role of the judiciary. Rather than interfering in political disputes, the Court emphasised that its responsibility is to ensure that constitutional boundaries established by law are respected. This distinction preserves the separation of powers by ensuring that each branch of government operates within its lawful authority.
The case has become a leading authority on judicial review of prerogative powers and is now regularly cited in constitutional law concerning executive accountability and the limits of governmental authority.
8.2 Critical Evaluation
Despite its constitutional importance, the judgment generated significant political controversy. Supporters argued that the Supreme Court acted appropriately by protecting democracy and preventing the executive from undermining Parliament during a period of exceptional constitutional significance. They viewed the decision as a necessary safeguard against abuses of executive power.
Conversely, critics argued that the Court entered an area traditionally governed by political convention rather than legal rules. Some commentators suggested that by creating a new legal test based on constitutional principles, the judiciary expanded its own constitutional role beyond previous limits.
Nevertheless, the unanimous nature of the judgment, delivered by all eleven justices, strengthened its authority and legitimacy. The Court consistently emphasised that it was not deciding political questions relating to Brexit but instead enforcing long-established constitutional principles concerning the rule of law and parliamentary sovereignty.
Overall, the judgment illustrates the increasing importance of constitutional principles within the UK’s uncodified constitution and demonstrates that even prerogative powers exercised in the name of the Crown remain subject to legal limits.
Conclusion
R (Miller) v The Prime Minister and Cherry v Advocate General for Scotland [2019] UKSC 41 represents a landmark decision in United Kingdom constitutional law. The Supreme Court unanimously confirmed that executive prerogative powers are not immune from judicial scrutiny where their exercise threatens the constitutional principles of parliamentary sovereignty and parliamentary accountability.
By declaring the prorogation unlawful and void, the Court reaffirmed the rule of law and demonstrated that constitutional principles impose meaningful legal constraints upon executive authority. The judgment has become one of the defining constitutional cases of the twenty-first century and continues to shape discussions concerning the balance of power between Parliament, the executive and the judiciary. It stands as a lasting affirmation that government power must always be exercised within the limits imposed by the constitution and remains accountable to both Parliament and the courts.
