UK Supreme Court Blog

EDITORS: Dan Tench, Emma Cross, Zainab Hodgson, Francesca Knight, James Warshaw and Natalie Haefner (CMS)
Hugh Tomlinson KC, Matthew Ryder KC, Dévante Gravesande-Smith and Rebecca Khan (Matrix)

The Supreme Court is about to embark on a politically momentous and contentious case. On December 5 it will begin hearing the government’s appeal against a High Court ruling which said parliament must pass legislation to trigger Article 50, the clause that would begin the United Kingdom’s withdrawal from the European Union.

While the Supreme Court is a new invention, the long history of UK law has failed to properly equip it for this kind of constitutional adjudication. The problem lies in the odd way in which the UK is organised legally: it is divided into three separate territorial jurisdictions – England and Wales, Scotland, and Northern Ireland – each with their own court systems, judiciaries and legal professions. The Supreme Court is the apex appeal court for all three jurisdictions – with the exception of criminal cases in Scotland. This means that much of the time it deals with normal civil or criminal cases (Scotland excepted) arising from those jurisdictions.

When it was set up by legislation in 2005, however, the Supreme Court also inherited responsibility from the Judicial Committee of the Privy Council for overseeing the devolution settlement – disputes about the powers of the devolved legislatures or executives.

Not a devolution matter

These different areas were distinguished in the legislation that set up the court. Section 41 of the Constitutional Reform Act 2005 specifies that on a normal appeal from a court, the judgment “is to be regarded as the decision of a court of” the relevant territorial jurisdiction. This means a judgment in a case from Northern Ireland, for instance, is only strictly binding in Northern Irish law.

However, this does not apply in respect of a “devolution matter” – so its rulings on these matters are binding in “all legal proceedings” in the UK, regardless of which jurisdiction they arose from. But a “devolution matter” is tightly defined in the act as proceedings on a bill referred by one of the law officers – the attorney-general or equivalents – or other proceedings which raise issues about the strict legal powers of devolved institutions.

But it does not include a case like the Article 50 one, known as the Miller case after investment manager Gina Miller, who brought the action against the government. Even if, as the Scottish and Welsh governments contend, the outcome of the case does affect devolved areas of policy or law, it isn’t a challenge to what the devolved assemblies and governments can legally do, so it isn’t a “devolution matter”.

All this means that on big questions arising on devolution, the Supreme Court has a UK-wide jurisdiction, akin to a federal constitutional jurisdiction, as in the US, Canada or Australia. But there has been no such innovation in other matters of fundamental constitutional importance that affect the UK as a whole. This includes cases which deal with the proper extent of the royal prerogative – the residual power of the government to act without parliamentary legislation. This is the key issue in the government’s appeal in the Miller case, as the government believes it has powers under royal prerogative to trigger Article 50 without going before parliament.

Unlike most lower courts, the Supreme Court has “judicial notice” of the law of all parts of the UK. But that does not alter the fact that when it makes a judgment – devolution matters aside – that ruling is confined to the jurisdiction from whence the appealed case comes.

So when it hears Miller, the Supreme Court must view what is in reality a UK-wide constitutional issue through the lens of the law of England and Wales alone, because the original ruling was made by the High Court of England and Wales. But the constitutional law of Scotland may, as many argue, be different from the constitutional law of England and Wales. The Scottish government, for instance, in the published statement of its arguments as an intervener in the Miller case, suggested that Scots law takes a different view of the extent of the royal prerogative.

Implications for the Miller case

In the Miller case, it is unlikely, although possible, that any divergence between Scots law and that of England and Wales in relation to the royal prerogative will be decisive in the Supreme Court’s reasoning.

While the decision – expected in early January – will strictly only be a judgment within the legal jurisdiction of England and Wales, we can confidently predict that the lower courts in Scotland and Northern Ireland will follow it, even though it is merely “persuasive” rather than “binding” in those jurisdictions.

But one day, the Supreme court will face a dispute between a Scots law interpretation (or perhaps a Northern Irish one) of the constitution and an English/Welsh one. That should be decided as a matter of UK constitutional law, drawing on both traditions and hearing counsel from both jurisdictions.

And in a recent ruling, the Supreme Court provided an excellent model for how that could happen, without having to change the Constitutional Reform Act. It said that the Privy Council, which is mostly made up of the same judges as those on the Supreme Court but in different hats, and who act as an apex appeal court for some Commonwealth countries, could itself certify that a decision would be binding in the jurisdiction of England and Wales – even if the appeal was from the Cayman Islands.

The Supreme Court should, in the Miller case, declare a similar approach to constitutional issues, and create a true UK law of the constitution.