This week, for the first time ever, all 11 Supreme Court judges will sit together to hear the Government’s appeal from the High Court’s judgment on Article 50. This will be the most important constitutional case the Supreme Court has ever heard.
The legal issue is not whether Brexit should go ahead. Rather, the question is how it should proceed. The Government has argued that the royal prerogative to conduct foreign policy authorises it to trigger Article 50. But the High Court ruled last month that the European Communities Act 1972, which gives effect to EU legal rights in UK law, limits this prerogative power.
If the Supreme Court upholds the High Court’s decision the Government will not be able to trigger Article 50 unless Parliament enacts new legislation. MPs or peers might refuse to support such legislation and the legislative process might introduce significant delay. Frustrating Brexit in this way seems to be the essential point of the litigation.
The High Court’s judgment surprised very many legal commentators. However, some have since asserted that the judgment is legally impregnable and that the Government is wasting its time with an appeal that is obviously doomed to fail. This is wishful thinking.
No appellate court should be overawed by the seniority of the judges at first instance. A judgment on appeal stands or falls on the strength of its reasoning. And the High Court’s judgment was badly mistaken.
True, the judgment affirms established constitutional principles. But in applying those principles, the Court misconceived how the 1972 Act gives effect to EU law. It misinterpreted that Act, wrongly taking it to imply that the Government was unable to seek the UK’s exit from the EU Treaties.
These missteps are partly attributable to the fact that the claimants argued their case very effectively, and the Government much less so. The judgment has since been trenchantly criticised by eminent constitutional law scholars, most powerfully and recently by Professor John Finnis in his Sir Thomas More lecture at Lincoln’s Inn. The Government now relies on many of these criticisms to explain why the High Court erred.
There are compelling legal reasons for the Supreme Court to allow the Government’s appeal. But this does not mean it will necessarily do so. The Supreme Court may double down on the High Court’s errors. Or the Court may give in to the temptation to depart from the law, either because the judges are sympathetic to the idea of frustrating Brexit or because they think it would simply be better if Parliament had to approve the Government’s plans by way of legislation.
The Supreme Court is not only hearing an appeal from the High Court. It also has to consider devolution issues first taken up in the Northern Ireland courts. The Scottish and Welsh Governments will address the Supreme Court in relation to these points.
So what should one look out for in the next four days? The dynamics amongst eleven judges and leading counsel will be interesting. But more important will be the clarity with which the Government makes its case. The failure of the Government at first instance to make the constitutional scheme – the interplay between EU law and domestic law – blindingly clear was crucial to its defeat. It must avoid the same mistake this week.
Much will turn on the extent to which the Government successfully challenges the framing of the litigation as an attempt to vindicate parliamentary sovereignty.
It is likely that some points to which the High Court gave relatively little attention in its judgment will resurface in argument before the Supreme Court. One might expect more argument about the constitutional and legal significance of the referendum itself, especially as the Court is now being invited to consider the constitutional conventions related to devolution.
The Supreme Court should allow the Government’s appeal. But it may not. In that eventuality one would expect the Government to introduce a very tightly drafted bill to Parliament, which would simply authorise triggering of Article 50. Yet it is possible that the Supreme Court might try to complicate this plan of action, whether by picking up the idea that Lady Hale floated in her recent lecture in Malaysia (that a simple Act of Parliament might not be sufficient) or by speculating that constitutional convention requires the consent of the devolved legislatures.
For the Court to introduce these complications would be madness. Hopefully, in the next few days the Government persuades it to allow the appeal and to avoid making a bad situation worse.
This article first appeared in The Telegraph, click here to read it on the newspaper’s website