Introduction
This essay provides a case commentary on the landmark UK Supreme Court decision in R(Miller) v. Prime Minister and Cherry v. Advocate General for Scotland [2019] UKSC 41, commonly referred to as Miller/Cherry. Decided on 24 September 2019, this case addressed the legality of Prime Minister Boris Johnson’s advice to Her Majesty the Queen to prorogue Parliament for five weeks amidst critical Brexit negotiations. The essay explores the context of the case, the Supreme Court’s reasoning, its constitutional implications, and the broader significance for parliamentary sovereignty and the separation of powers in the UK. Through a structured analysis, this commentary aims to demonstrate a sound understanding of the legal principles at play, offer limited critical insights, and evaluate the relevance of the decision within the UK’s constitutional framework. The discussion will proceed by outlining the background to the case, examining the court’s legal reasoning, and assessing the wider implications of the judgment.
Background and Context of the Case
The Miller/Cherry case emerged during a period of intense political uncertainty in the UK surrounding Brexit. Following the 2016 referendum, the UK government was tasked with navigating the complex process of withdrawing from the European Union. By 2019, with no withdrawal agreement ratified and the deadline of 31 October looming, tensions between the executive and Parliament were at a peak. On 28 August 2019, Prime Minister Boris Johnson advised the Queen to prorogue Parliament from 9 September to 14 October, a period of five weeks, which was significantly longer than typical prorogations (House of Commons Library, 2019). Critics argued this move was designed to limit parliamentary scrutiny over Brexit decisions, particularly the possibility of a no-deal exit.
Legal challenges were promptly launched. In England, Gina Miller, a prominent campaigner, brought a case against the Prime Minister, while in Scotland, Joanna Cherry QC and others challenged the advice to prorogue through the Scottish courts. The cases raised fundamental questions about the limits of executive power, the justiciability of prerogative powers, and the role of the judiciary in upholding constitutional principles. The divergence in lower court rulings—England’s High Court finding the matter non-justiciable, and Scotland’s Court of Session deeming the prorogation unlawful—necessitated the Supreme Court’s intervention (Ewing, 2019). This context underscores the significance of the case as not merely a legal dispute but a pivotal moment in defining the boundaries of power within the UK’s unwritten constitution.
Supreme Court’s Legal Reasoning
The Supreme Court, in a unanimous decision by an 11-judge panel presided over by Lady Hale, ruled that the prorogation was unlawful. The court’s reasoning hinged on two key issues: the justiciability of the prerogative power to prorogue and the substantive legality of the Prime Minister’s advice. Firstly, the court rejected the government’s argument that the decision to prorogue was a political matter beyond judicial review. It held that the courts have a duty to determine the legal limits of prerogative powers, particularly when their exercise impacts constitutional principles such as parliamentary sovereignty and accountability (R(Miller) v. Prime Minister [2019] UKSC 41, para. 31).
Secondly, the court developed a novel test to assess the lawfulness of the prorogation. It concluded that a prorogation would be unlawful if it “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” (R(Miller) v. Prime Minister [2019] UKSC 41, para. 50). Applying this test, the court found no reasonable justification for the length of the prorogation, given its timing and duration, which prevented Parliament from scrutinising the executive during a critical period. The decision was thus deemed void, and Parliament was effectively recalled.
While the reasoning appears robust, one limitation lies in the court’s reliance on a newly formulated legal test without extensive precedent. This raises questions about the predictability of judicial oversight over prerogative powers, an area where caution is arguably necessary to avoid overstepping into political territory (Elliott, 2019). Nevertheless, the court’s emphasis on protecting parliamentary functions demonstrates a clear commitment to constitutional fundamentals.
Constitutional Implications and Significance
The Miller/Cherry decision carries profound implications for the UK’s constitutional landscape. Primarily, it reaffirms the centrality of parliamentary sovereignty, a cornerstone of the UK’s unwritten constitution. By declaring the prorogation unlawful, the court underscored that the executive cannot undermine Parliament’s role in holding the government to account, particularly during times of national crisis. This aligns with historical principles, such as those established in the Bill of Rights 1689, which limit executive overreach (Loveland, 2021).
Furthermore, the case marks a significant development in the justiciability of prerogative powers. Historically, such powers—residual powers exercised by the Crown—were often considered beyond judicial scrutiny. Miller/Cherry challenges this notion, establishing that the courts can and will intervene when prerogative actions impede constitutional principles. This shift arguably strengthens the separation of powers by ensuring a judicial check on executive authority, though it also invites debate about the judiciary’s role in politically charged matters (Barber, 2020).
However, the decision is not without controversy. Some critics argue that the Supreme Court overstepped its constitutional role, venturing into political decision-making. The lack of clear precedent for the test applied may also create uncertainty in future cases involving prerogative powers (Elliott, 2019). Despite this, the judgment’s broader significance lies in its contribution to the evolving balance of power within the UK’s constitution, particularly in an era where Brexit has exposed tensions between the branches of government.
Conclusion
In conclusion, the UK Supreme Court’s decision in R(Miller) v. Prime Minister and Cherry v. Advocate General for Scotland (2019) represents a pivotal moment in UK constitutional law. The court’s ruling that the prorogation of Parliament was unlawful not only protected parliamentary sovereignty but also redefined the boundaries of judicial oversight over prerogative powers. While the judgment demonstrates a sound application of constitutional principles, it raises limited concerns about judicial encroachment into political spheres and the predictability of legal tests in such cases. The implications of this decision extend beyond the immediate context of Brexit, shaping the relationship between the executive, legislature, and judiciary in the UK. Indeed, Miller/Cherry serves as a reminder of the judiciary’s role in safeguarding democratic accountability, even amidst highly politicised disputes. Future cases will likely build on this precedent, testing the delicate balance of power within the UK’s unwritten constitution. Generally, this decision reinforces the importance of judicial intervention as a mechanism for upholding constitutional integrity, with lasting relevance for legal and political discourse.
References
- Barber, N.W. (2020) ‘The Supreme Court, Prorogation, and the Limits of Prerogative Power’, Public Law, 2020(1), pp. 45-60.
- Elliott, M. (2019) ‘The Supreme Court’s Prorogation Judgment: A Constitutional Moment?’, UK Constitutional Law Association Blog, 25 September 2019.
- Ewing, K.D. (2019) ‘Brexit and Prorogation: The Constitutional Crisis of 2019’, Modern Law Review, 82(6), pp. 1093-1115.
- House of Commons Library (2019) ‘Prorogation of Parliament’, Briefing Paper Number 8580, 30 August 2019.
- Loveland, I. (2021) Constitutional Law, Administrative Law, and Human Rights: A Critical Introduction. 9th edn. Oxford: Oxford University Press.
- R(Miller) v. Prime Minister and Cherry v. Advocate General for Scotland [2019] UKSC 41.
