By Mark McKeown, Associate and Hannah Starritt, Solicitor

The Miller case has brought to the fore two elements of the United Kingdom’s part-written constitution. One, the Royal Prerogative, is ancient and unwritten; the other, the European Communities Act 1972 (the ECA), is modern and enshrined in statute.

Both are, however, of vital importance to the mechanics of the governance of the UK.  Here, we give some background on each, and then consider their role in Miller.

The Royal Prerogative

The Royal Prerogative is the general term for a group of powers which historically were exercised by the monarch, but the majority of which are now exercised by the UK Government either acting alone or by advising the reigning monarch. Its scope is vague, and where there is uncertainty as to whether or not a particular type of prerogative power exists, the courts are the ultimate arbiters.

The main areas where the Royal Prerogative is exercised today are:-

  • The judicial system (e.g. the pardoning of convicted offenders).
  • The bestowing of honours (e.g. the conferring of honours in the Queen’s Birthday and New Year’s Honours List, and the creation of Members of the House of Lords).
  • Powers relating to the legislature (e.g. the granting of Royal Assent by the monarch to Bills in Parliament).
  • Powers relating to the armed forces (e.g. the position of the reigning monarch as Commander-in-Chief of the Armed Forces).
  • Powers relating to foreign affairs (e.g. the making of treaties, the declaration of war and the issuing of passports).

The European Communities Act 1972

On 1st January 1972, the UK joined the European Economic Community, or what is now known as the European Union (EU). The European Communities Act 1972 (ECA), the full title of which is “an Act to make provision in connection with the enlargement of the European Communities to include the UK together with (for certain purposes) the Channel Island, the Isle of Man and Gibraltar”, was enacted to give effect to European Community law in the national legal systems in the UK to binding obligations and rights.

Due to the limitations set down by prerogative powers, the Crown could not have ratified the accession of the UK to the EU under the Communities Treaties unless Parliament had enacted legislation. Therefore, the ECA was enacted to allow for EU law, including the rights and obligations, to be given effect in UK domestic law.

The ECA is the sole example of legislation which confers precedence on EU law. This means that if there is a clash between UK and EU law, EU law will take precedent. It also means that the European Court of Justice interprets EU law with judgements that are binding on all Member States. It imposed EU rights and obligations on UK law, such rights include workers’ rights and rights to free movement.

What role did the Royal Prerogative and the ECA play in the Miller case?

In the High Court, the UK Government made the argument that the Royal Prerogative has always included powers relating to foreign affairs and that it is, therefore, for them to invoke Article 50, thereby carrying out the democratically expressed wishes of the UK electorate. They considered that they could invoke Article 50 lawfully without the need to consult Parliament.

The difficulty with the UK Government’s approach is that whilst the Royal Prerogative certainly allows it to conduct foreign affairs and make treaties, such treaties only have effect because the UK Parliament enacts legislation to do so.  The argument made by the Claimants was that because the UK entered the EU by means of an Act of Parliament, and leaving the EU will require the repeal of the ECA, such a repeal can only be carried out by a subsequent Act of Parliament to that effect.

The Claimants’ argument therefore is that rather than use its prerogative power, the UK Government would need to table legislation in Parliament, so that it had authority to invoke Article 50 and in due course repeal the ECA, having made the notification.

The High Court agreed with the Claimants, and the UK Government has appealed the decision to the UK Supreme Court, which will begin hearing the appeal on 5th December.