Analysis - Article 50 | University of Oxford
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Analysis - Article 50

Published 28 July, 2016.

Article 50: Playing constitutional Russian roulette?

Alison Young, Professor of Public Law, University of Oxford
Fellow and Tutor in Law, Hertford College.

Alison YoungAlison Young
Brexit has far-reaching consequences for the economy, the UK’s relations with Europe and the rest of the world and the integrity of the Union. As the country’s politicians try to navigate their way through these troubled waters, its lawyers are trying to steer their way through the equally choppy waters of Article 50 of the Treaty on European Union. What is needed to trigger Article 50 and, perhaps more pertinently, who gets to decide?

Article 50 allows a member state to decide to withdraw from the EU, according to its own constitutional requirements. Once the decision is made, the member state is required to notify the European Council, triggering a two- year negotiation period which may be extended by agreement. The EU Treaties no longer apply to the UK once this period comes to an end, or once a withdrawal agreement has been reached and has entered into force. This may seem clear enough, but in a country with no codified constitution which draws its constitutional requirements from legislation, the common law and convention, it is difficult to know the UK’s constitutional requirements for determining a decision for the purposes of Article 50.

One certainty is that the referendum itself is not a decision; it is an expression of the wishes of the public. The European Union Referendum Act 2015 placed no legal requirement on the Government to respond to the referendum – although ignoring the referendum outcome would have political consequences.

This appears to be where the certainty ends. Government lawyers argue that all that is needed is an exercise of a prerogative power – i.e. a non-statutory power exercised by the executive on behalf of the Crown. However, others claim there is a need for legislation. There is a now a legal challenge, specifically asking the courts to determine whether an Act of Parliament is needed to trigger Article 50.

The argument for an Act of Parliament stems from the nature of the relationship between statutory and prerogative powers. The common law makes it clear that, to the extent that the two conflict, statutory provisions override prerogative powers. If, for example, legislation clearly stated that a decision to withdraw from the European Union could only be made by an Act of Parliament, the courts would strike down a triggering of Article 50 by prerogative as unlawful. However, there is no such legislative provision.

The argument in favour of an Act of Parliament is more subtle and rests on a series of steps, all of which are subject to potential objections. Firstly, some claim that the common law prevents ministers from exercising prerogative powers in a way that may remove or restrict rights. Second, Article 50, once triggered, cannot be reversed, leading to the inevitable removal of EU rights. Yet, these rights have become part of UK law, incorporated through legislation: the European Communities Act 1972. Thirdly, the European Union Act 2011 makes it clear that any rights in European Union law are only recognised in UK law by virtue of an Act of Parliament. Put these three stages together and there is the argument that just as we need an Act of Parliament to incorporate European Union law rights into UK law, so we also need an Act of Parliament to remove those rights.

Although it is arguable that the common law prevents ministers from exercising prerogative powers to remove rights found in legislation, there is no clear judicial decision definitively supporting this interpretation. While Article 50 does not expressly enable us to stop the negotiation procedures once triggered, there are nevertheless arguments that the UK could change its mind even after this has been done. Arguably, we could stop the process of leaving the EU before the negotiation period ends or a withdrawal agreement has been put into force.  The provisions of the European Union Act were enacted to make it clear that it was legislation, and by implication not the common law, which governed the relationship between UK law and European Union law. Its provisions outline how power is transferred from the UK to the European Union, not power travelling in the opposite direction.

If that was not complicated enough, there is the issue of who decides whether an Act of Parliament is needed and makes the declaratory order. Once issued, the government would also have to decide how to respond. It is not beyond the realms of possibility that the UK courts would refer the matter to the Court of Justice of the European Union to determine whether the Article 50 process could be reversed once triggered. The UK courts would then have to apply this court’s interpretation of Article 50. Even if the court concludes that an Act of Parliament is not needed, there is still the issue of whether Article 50 can be triggered by the Prime Minister alone, or whether it needs an Order in Council, requiring the approval of the Privy Council.  

Although much of this confusion is due, in part, to the UK’s lack of a codified constitution, even if we had one it could not provide for every eventuality. A codified constitution would also probably have had debates on the meaning of legal terms, interpreted either according to the intentions of its enactors or adapted to reflect current values.

Hopefully, the fact we have a more flexible constitution means we can resolve some of the issues not just by interpreting legal terms but also by paying attention to what best serves the UK’s parliamentary democracy. We live in interesting constitutional times, and only time will tell whether we can navigate our way smoothly through these difficulties.