Brexit On Ice? Court Rules That Only UK Parliament Can Trigger Article 50

Executive Summary

Earlier today, the High Court of Justice ruled that the U.K. government does not have the constitutional capacity to trigger the U.K.'s withdrawal from the European Union without further primary legislation being passed. This decision is likely to delay, potentially significantly, the filing of the U.K.'s Article 50 notice with the European Council, further extending the uncertainty over the timing and the terms of the U.K.'s exit from the European Union ("EU").

Background

During the course of October 2016, a number of separate claims were commenced in the High Court concerning the U.K. government's constitutional capacity to give notice under Article 50 TFEU of the U.K.'s intention to withdraw from the EU. These various proceedings were joined and heard together as Santos & Miller v. Secretary of State for Exiting the European Union.

The primary purpose of the relevant claims was for the High Court to determine whether the U.K. government may lawfully use what are referred to as "prerogative powers" to serve a notification under Article 50 TFEU of the U.K.'s intention to withdraw from the EU. These prerogative powers are a quirk of U.K. constitutional law, which allows the government at the time (acting...