Dr Sam Fowles comments on two major constitutional cases on the BBC and in The Independent.
In Wightman and Others v Secretary of State for Exiting the EU the Court of Justice of the European Union ruled that the UK can unilaterally revoke its Article 50 notification. This means that, if Parliament decides to do so, it can cancel Brexit.
In Wilson and Others v The Prime Minister, which will be decided today, the High Court will decide whether the claimants, a group of UK citizens living in continental Europe, can proceed to argue that the result of the 2016 referendum is vitiated by the unlawful actions of certain "leave" campaigners. Although the Court cannot compel the Prime Minister to stop Brexit, it can require her to take a second look at the legitimacy of the 2016 referendum.
Both cases will have a significant impact on the UK constitution both for Brexit and beyond.
If Wilson is decided in the claimants' favour, it will mean that illegality fundamentally taints an election, even where no such provision is made in statute. This will mean that the Government will have to re-think Brexit and will strengthen calls for a People's Vote.
Wightman creates a new approach to the interpretation of treaties. Where it was previously believed that a state cannot rely on its internal law to avoid its treaty obligations, Wightman shows that a state can rely on those obligations where they are referenced in the treaty itself.
As regards Brexit, it tips the constitutional balance in favour of Parliament, giving it the ultimate decision as to whether to revoke the Article 50 notification, thereby strengthing democratic control of the Brexit process.
Sam Fowles is a member of the Cornerstone Public and Constitutional Law team and has advised clients ranging from MPs and NGOs to individuals and local government about all aspects of Brexit. He advised a third party on the Wilson case.