Brexit and the EU Court

EU Treaty provisions

Article 50 (1) of the Treaty on European Union (TEU) states: “Any Member State may decide to withdraw from the Union in accordance with its own constitutional requirements”. Article 50 (2) TEU states: “A Member State which decides to withdraw shall notify the European Council of its intention”.

Referral to the Court of Justice of the EU?

After the High Court judgment in Miller on 3 November 2016 on whether the Government could trigger the start of the EU exit process under Article 50 TEU using Prerogative powers, some media reports suggested that the Court of Justice of the European Union (CJEU) would have the last word on the use of the Royal Prerogative.

The interpretation of Article 50 TEU, if one were needed, would be a matter of EU, not UK, law. Under Article 267 of the Treaty on the Functioning of the European Union (TFEU) there could be a role for the CJEU in determining whether an Article 50(2) notice can be withdrawn if a Member State which has served notice of an intention to withdraw changes its mind.

But are questions about the decision to trigger Article 50 under national constitutional arrangements relevant to the CJEU?

The ‘acte clair’ doctrine

If a court of last instance has some uncertainty as to the correct interpretation of EU law, it must refer a question on the interpretation of EU law or the EU Treaties to the CJEU, but not if the national court decides something is clear “beyond reasonable doubt”. This is known as the ‘acte clair’ doctrine, and it has been established in the case law of the CJEU (largely in CILFIT).

The case of Gina Miller at the High Court

In Miller the Court recorded it as common ground that the Article 50(2) notice is irrevocable and therefore the High Court did not rule on this point. It ruled that the UK Government could not trigger Article 50 TEU without parliamentary involvement. The irrevocability of Article 50 was an important underlying factor, even though the Court did not rule on this point.

The Government has appealed the decision to the Supreme Court. Its skeleton grounds for appeal do not mention irrevocability.

The question of whether a notice of withdrawal can be revoked

There is a general principle of international law, set out in Article 68 of the Vienna Convention on the Law of Treaties, that a notification of intention to withdraw from a treaty “may be revoked at any time before it takes effect”. This provision does not override any specific arrangements in a treaty.

The EU Treaty is silent on this matter, and although the parties to the Miller case assumed that notice of withdrawal is irrevocable, there are possible arguments, and a preponderance of academic opinion, to the contrary.

If the CJEU were to rule on the revocability question, it would interpret purposively and not according to academic opinion. While academic views are non-determinative, the CJEU might “take account of” what the Vienna Convention says.