The rule of recognition and sources of law in <i>Miller</i>

The UK Supreme Court’s judgment in Miller renews attention in the sources of law, particularly treaty-based sources. The Court held that the UK Government was not permitted to use the foreign affairs prerogative to notify the European Council of its intention to withdraw from the EU under Article 50(2) TEU without authorisation from an Act of Parliament.The majority’s reasoning has been criticised, including its twin claims that EU law is a direct, independent and overriding source of law and that UK membership of the EU did not alter the UK’s rule of recognition. I will begin by arguing that these twin claims are defensible.At the same time, Miller does leave unresolved important questions of constitutional law. Is Miller a one-off case, not to be repeated again in our lifetimes, or might it have implications for other treaty-based sources that are given effect under domestic legislation? The paper’s second aim is to explore this question, and also to offer proposals to address some key uncertainties that remain