Richard Eccles and Cathal Flynn

Richard Eccles and Cathal Flynn

High Court’s ruling that Parliamentary Approval is required to invoke Article 50 of the Treaty on European Union

The Supreme Court hearing on invoking Article 50 in early December made the headlines and saw approximately 300,000 people tune into the live stream of proceedings, but while we wait for judgment it is useful to remember exactly how this all started.

On 3 November 2016, the High Court in its ruling in R (Miller) v. Secretary of State for Exiting the EU ("Miller") firmly rejected the UK Government’s argument that the Prime Minister could invoke Article (“Art.”) 50 of the Treaty on European Union (the “TEU”) without the prior authorisation of Parliament. The implication of the judgment was that legislation will be needed to trigger Art. 50.

The Question before the High Court

The issue for the High Court and now the Supreme Court in Miller was/is whether, as a matter of UK constitutional law, the Government, through the Prime Minister, can use Crown prerogative powers to trigger Art. 50 of the TEU, or whether the prior authorisation of Parliament is needed.

Parliamentary Sovereignty

The most fundamental rule of the UK constitution is that Parliament is sovereign and can make and unmake any law. This includes the legislation that facilitated the entry of the UK into the EU (the European Communities Act (1972) (as amended) (the “ECA 1972”)).

Crown Prerogative

According to the High Court, the exercise of Crown prerogative powers is subject to constitutional limitations. Crown prerogative cannot therefore be invoked to displace primary legislation. However, the Crown does have prerogative to conduct international relations on behalf of the UK, including in respect of the making and unmaking of international treaties on behalf of the UK.
The High Court also accepted that Crown prerogative cannot alter UK law or confer or remove rights of individuals under domestic law without the intervention of Parliament.

The Arguments of the Parties

The Government argued that, as the conduct of international relations falls within the prerogative powers of the Crown, the Government itself can affect UK withdrawal from the EU by giving notice under Art. 50 TEU. It further argued that, as such power could only be removed by primary legislation using express words to that effect; neither the ECA 1972 nor any other act of Parliament abrogated this aspect of Crown prerogative as they are silent on the issue.

The complainants' argument

The complainants argued that the ECA 1972 leaves no room for a Crown prerogative power to invoke Article 50 TEU because the 1972 Act allows for the accrual of rights under domestic law by incorporating EU law into UK law. Any other interpretation would, according to the complainants, conflict with the fundamental principle that only Parliament can take away rights conferred by statute.

The Court’s Decision

The High Court firmly rejected the Government’s argument and declared that Art. 50 could only be invoked with the authorisation of Parliament.

The High Court held that the Government’s argument was contrary to the constitutional principle of Parliamentary sovereignty. The Court stated that the “wide and profound” changes in domestic law created by the ECA 1972 made it “especially unlikely” that Parliament intended to leave the power to effect a withdrawal from the EU in the hands of the Crown.

The Nature of an Art. 50 Notice

The High Court did not have to consider the nature of Art. 50 notice; i.e. whether it is revocable or irrevocable. This is because the Government did not dispute the contention of the complainants that Art. 50 notice is irrevocable.

Whether or not the Supreme Court will be compelled to address this question will depend on the extent to which the Supreme Court considers that the Art. 50 notice will potentially affect relevant rights. The nature of an Art. 50 notice is a contentious issue of EU law that has not yet been tested either before the national or EU courts. This question could, in itself, add an additional layer of controversy and complexity.

Conclusion and Possible Outcomes

Unless the Supreme Court overturns the High Court’s decision in Miller, the Government will have to seek the approval of Parliament, possibly through new legislation, before invoking Art. 50. This risks, at the least, delaying the Government’s timetable for triggering Art. 50. A decision by the Supreme Court to uphold the High Court’s judgment in Miller could also give rise to a number of potentially unwelcome outcomes for the UK Government.

Whilst the House of Commons could be expected to support the measures to reflect the referendum result, it is possible that the need for the Parliament’s consent could lead to a lengthy debate. This could significantly delay the timetable for invoking Art. 50. There is also a risk that the House of Commons could use this process as an opportunity to allow for greater Parliamentary scrutiny and control in the negotiation process itself that will follow the triggering of Art. 50. There is also a potential for the House of Lords to delay (as opposed to block) the invoking of Art. 50.