On January 24, 2017, the UK Supreme Court handed down its judgment in the case of R (on the application of Miller and another) (Respondents) v. Secretary of State for Exiting the European Union (Appellant) [2017] UKSC 5. The case concerned the process to be followed to effect the UK’s withdrawal from the European Union and, in particular, whether the UK government may commence the UK’s withdrawal using executive powers, or whether Parliamentary approval is required. The Supreme Court held, by majority, that the UK government cannot commence the UK’s withdrawal from the EU without the approval of Parliament.

The Supreme Court held that withdrawal from the EU fundamentally changes the UK’s constitutional arrangements, and explained that the UK Constitution requires changes of such magnitude to be taken by Parliament. The UK Government already has, however, announced its intention to place a bill before Parliament that would grant the government the necessary approval to commence the withdrawal process. Notably, the Supreme Court’s judgment indicates that the form of such a bill is up to Parliament to decide, and that such a law may be “very brief.” The ruling has nevertheless been seized upon by opposition parties, who have suggested that they plan to use the ruling to ensure that the government obtains the right deal for the UK.