R (on the application of Miller) v Prime Minister [2019] UKSC 41

Court: Supreme Court

Facts : In August 2019, Prime Minister Boris Johnson advised the Queen to prorogue Parliament for five weeks. This action was seen as preventing Parliament from scrutinizing the Government’s Brexit agenda. Gina Miller challenged the prorogation, arguing it violated parliamentary sovereignty and accountability.

Issue: Is the Prime Minister’s advice to prorogue Parliament justiciable, and if so, was the prorogation lawful?

Held: The Supreme Court ruled that the prorogation was unlawful, as it had the effect of frustrating Parliament's ability to carry out its constitutional functions without reasonable justification.

Key Judicial Statement: The court emphasized that prerogative powers must respect fundamental constitutional principles like parliamentary sovereignty and accountability.

💡 Leveluplaw: The exercise of prerogative powers is justiciable when it threatens constitutional principles such as parliamentary sovereignty.