The Supreme Court as a Constitutional Court: Reflections on Cherry/Miller

In a unanimous single judgment, the eleven justices of the UK Supreme Court have ruled that the purported prorogation of Parliament for five weeks from 9 September to 14 October was unlawful because the advice of the Prime Minister to Her Majesty the Queen was unlawful.

The Supreme Court has declared that Parliament does not stand prorogued but it is for the authorities of the Houses of Parliament and Government and Opposition to decide what Parliament will now do. This is entirely consistent with what happened after the ruling of the Supreme Court in the first Miller case in which the Supreme Court held that the Government needed the authority of an Act of Parliament to trigger the Article 50 process for withdrawal from the European Union. The Supreme Court did not, and would not, instruct Parliament to legislate and it has not now instructed Parliament as to what it should do following today’s declaration.

There is much that can be – and will be – written about the judgment. It arose from distinct legal proceedings in the Scottish courts – in a petition for judicial review brought by Joanna Cherry MP QC and more than seventy parliamentarians supported by Jolyon Maugham QC who crowd-funded the case – and in the English courts – in an application for judicial review brought by Gina Miller. Whereas Ms Miller lost before the English Divisional Court, Ms Cherry succeeded before the Inner House of the Scottish Court of Session which held that the Government had acted unlawfully in using prorogation to “stymie” Parliament in the period leading up to the UK’s withdrawal from the EU. Appeals in both cases came before the Supreme Court.

But today’s judgment is much more than an apex appeal in two separate but linked judicial review cases. It is also a constitutional ruling of a court that clearly sees itself not just as a “supreme court’ but as the constitutional court of the United Kingdom with the responsibility to uphold and apply the constitution of the United Kingdom. It noted that:

Although the United Kingdom does not have a single document entitled “The Constitution”, it nevertheless possesses a Constitution, established over the course of our history by common law, statutes, conventions and practice. [para 39]

It continued:

… the courts have the responsibility of upholding the values and principles of our constitution and making them effective. It is their particular responsibility to determine the legal limits of the powers conferred on each branch of government, and to decide whether any exercise of power has transgressed those limits. [para 39]

There was always a risk in this case of a certain lack of fit between the constitutional nature of the underlying political struggle between the Executive and Parliament, and the legal tools available through which to frame the dispute in legal terms. The UK’s system of court-based public law has emerged through the rise of proceedings in judicial review which determines the limits of public power through the application of principles of administrative law. The tools and techniques of administrative law – and in particular the grounds of judicial review developed by the courts – are well-known to public lawyers. Decisions taken by public authorities must not entail procedural impropriety – failure to abide by mandated procedures; breaches of natural justice; bias – or illegality – acting ultra vires or for an improper purpose or by taking into account irrelevant considerations – or otherwise irrational or unreasonable. This is a flexible toolkit that can be applied to a wide range of decision-makers. The recognition of fundamental rights both at common law and more directly through the Human Rights Act has deepened the substantive review of the legality of decision-making and extended it beyond administrative action to the review of Acts of Parliament for their compatibility with fundamental rights.

In the proceedings before the Supreme Court, lawyers on all sides delved into this body of law to frame their claims about the lawfulness or otherwise of the actions of the Prime Minister. It seemed as if much might turn on whether the Prime Minister was seeking to use a recognised power to prorogue for an improper purpose or was otherwise motivated by improper concerns. Yet translating this from the administrative law realm – where a court might be asked to determine whether a statutory power was being used for a purpose other than that for which it was intended by Parliament – to the constitutional realm of the prerogative power to prorogue was not without its difficulties. Does prorogation have a proper purpose and what sort of evidential basis would be needed to determine if a use was improperly motivated? Would sworn affidavits from the Prime Minister and his officials be needed to work out what was in their minds when they sought a prorogation? The Supreme Court largely side-steps these problems by taking a more resolutely constitutional path.

At the heart of the judgment is the proposition that there are two key constitutional principles: the sovereignty of Parliament and parliamentary accountability of the Executive. Parliamentary sovereignty is typically reduced to the maxim that Parliament can make or unmake laws which it is the duty of the courts to interpret and apply. But as the Supreme Court also noted, the sovereignty of Parliament would be undermined ‘as the foundational principle of our constitution’ if a prerogative power to prorogue could be used to ‘prevent Parliament from exercising its legislative authority’; a point made forcibly by Professor Paul Craig in a highly influential blog on the eve of proceedings before the Supreme Court. As for parliamentary accountability, the Court equally viewed this as a cardinal constitutional principle that could be frustrated by an unduly long prorogation. All of which left the Court to ask:

So the same question arises as in relation to Parliamentary sovereignty: what is the legal limit upon the power to prorogue which makes it compatible with the ability of Parliament to carry out its constitutional functions? [para 48]

The Supreme Court formulated the relevant test to be applied in the following way:

a decision to prorogue Parliament (or to advise the monarch to prorogue Parliament) will be unlawful if the prorogation 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. In such a situation, the court will intervene if the effect is sufficiently serious to justify such an exceptional course. [para 50]

By looking at the effects rather than the motive and by determining whether the effect is an interference with constitutional principles that lacks a reasonable justification, the Supreme Court deploys a test that is certainly analogous to situations where courts engage in interest-balancing. In other words, the Executive does have a legitimate interest in prorogation to start a new parliamentary session. Prorogation does have effects that include the cessation of normal parliamentary business and the loss of Bills in progress. The longer the prorogation the more serious the effect on Parliament’s interests in ensuring it can perform its constitutional functions. Accordingly, a longer prorogation than normal demands a higher level of justification and reason-giving. Therefore, without getting into any questions about motive or purpose the Supreme Court could state:

It is impossible for us to conclude, on the evidence which has been put before us, that there was any reason – let alone a good reason – to advise Her Majesty to prorogue Parliament for five weeks, from 9th or 12th September until 14th October. We cannot speculate, in the absence of further evidence, upon what such reasons might have been. It follows that the decision was unlawful. [para 61]

The Court did not venture further in explicitly proposing a proportionality-based balancing of interests but it is still clear from the judgment that the greater the interference with the protected constitutional principles – and so increasing the seriousness of the effects on the capacity of Parliament to exercise its functions – the greater the justificatory demands. That feels like a constitutional style of adjudication.

Nonetheless, the cautious approach of judicial review may temper any potential constitutional overreach. Early on in the judgment, the Court identifies that it is the Prime Minister who has the constitutional responsibility to have regard to all relevant interests ‘including the interests of Parliament’ and so interest-balancing is first of all a matter for politics. However, it is clear that how that is done, and the justification provided for the effects on the interests of Parliament, is open to judicial review and is justiciable.  In the extreme case, it will be found to be unlawful.

Brexit is putting UK politics and its constitution under considerable strain. However, today’s ruling is an important signal than in a constitutional monarchy, the constitution sill matters and the Supreme Court is willing and able to play its role as a constitutional court.

NB: The author was part of the legal team advising the petitioners in the judicial review sought by Joanna Cherry MP QC and other parliamentarians. This blog is written in a purely personal capacity and does not purport to represent the views of the petitioners or the legal team. It is a wholly personal academic reflection on the implications of the Supreme Court’s ruling.

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