Article 50, parliamentary authorisation and the Sewel Convention

The Divisional Court’s ruling in R (Miller) v Secretary of State for Exiting the European Union that parliamentary authorisation is required before the Prime Minister can give notice of the UK’s intention to withdraw from the EU under Article 50(2) TEU raises the question of what role, if any, the devolved legislatures will have in that process.

The Divisional Court in Miller did not consider it necessary to address this issue. However, it was central to the earlier decision of the Northern Irish High Court in McCord. McCord, in contrast to Miller, concluded that prior parliamentary authorisation was not required to trigger Article 50. But even if it was, the court took the view that such legislation would not engage the Sewel Convention at least as it applies in Northern Ireland because it would relate to “excepted matters” under the Northern Ireland Act 1998 (NIA) (i.e., matters outwith the scope of devolved competence).

Nevertheless, there is an argument to be made that, if the Supreme Court upholds the Divisional Court’s reasoning in Miller, the Sewel Convention would be engaged, at least as far as Scotland is concerned.