THE DECISION OF THE SUPREME COURT in the Prorogation case — R(Miller) v Prime Minister or “Miller 2” — is the most important constitutional law case of this century. No court had previously exercised control over the relationship between Crown and Parliament in the way the Supreme Court did when it held that Her Majesty’s decision on prime ministerial advice to prorogue Parliament was “unlawful, null and of no effect”, with the legal consequence that the Commissioners who entered the House of Lords were to be treated as carrying “a blank piece of paper”.
It is true that, as the court said, the circumstances that arose in September 2019 were exceptional. Parliament was deadlocked and the two-year negotiating period allowed by Article 50, as extended, was shortly to expire. It does not follow, though, that Miller 2 will be treated as a special case decided on its own facts. It will be cited by advocates retained by politically active litigants: “If the court were able to intervene in those circumstances, notwithstanding the intensely political nature of the underlying issues, then…”.
The case is of great constitutional importance because of the court’s determination that the matter was justiciable. If a matter is justiciable, it is amenable to judicial control by the application of legal rules or standards. Defining the boundaries of what may be referred to as the zone of non-justiciability is an exercise that can only be carried out by the courts. It is an exercise of great constitutional delicacy.
Johnson’s limited options
IN OCTOBER 2016, THE PRIME MINISTER, Theresa May, announced her intention to give notice under Article 50 of the Treaty on European Union. Gina Miller and others brought legal proceedings, asserting that notice could not be lawfully given without the authority of an Act of Parliament.
These proceedings (“Miller 1”) did not raise any issue of justiciability. The courts were bound to answer the question raised. The Divisional Court held unanimously that legislation was required before an Article 50 notice could be served. The individual judges were, outrageously, the subject of vituperative personal criticism in the press. The Supreme Court upheld the decision by an 8-3 majority.
The practical effect of Miller 1 was negligible. Within a few weeks Parliament passed the European (Notification of Withdrawal) Act 2017, which received Royal Assent on 16 March 2017. Notification of withdrawal was given two weeks later.
In May 2017 Theresa May chose to call a general election and lost her majority. On 26 June, 2018, the European Union (Withdrawal) Act 2018 came into force. It defined “exit day” as 29 March 2019, but this could be (and in due course was) extended by statutory instrument. Section 13 of the Act required parliamentary approval of
