R (Miller) v Secretary of State for Exiting the European Union

R (Miller) v Secretary of State for Exiting the European Union is a United Kingdom constitutional law case decided by the United Kingdom Supreme Court on 24 January 2017, which ruled that the British Government (the executive) could not initiate withdrawal from the European Union by formal notification to the Council of the European Union as prescribed by Article 50 of the Treaty on European Union without an Act of Parliament first being passed to give the government Parliament's permission to do so. Two days later, the government responded by bringing to Parliament the European Union (Notification of Withdrawal) Act 2017 for first reading in the House of Commons on 26 January 2017.

Source: Wikipedia — R (Miller) v Secretary of State for Exiting the European Union (CC BY-SA 4.0)