- John StantonJohn StantonSenior Lecturer in Law at The City Law School, City, University of London
- and Craig PrescottCraig PrescottLecturer in Law, Bangor University
This chapter considers ‘illegality’ as a ground of judicial review. Illegality is one of the three main grounds of judicial review as outlined by Lord Diplock in Council of Civil Service Unions & Others v Minister for the Civil Service. Broadly, the aim of this ground of judicial review is to ensure that public authorities act within the scope of their powers. This means that illegality is a wide ground of judicial review and is best considered as an umbrella term for a range of different ways in which a decision by a public authority can be challenged. A decision can be challenged under this ground of judicial review on the basis that the public authority lacks the power to make the decision in the first place, or if it does have the power, then the power has been exercised incorrectly.