Judicial Review Grounds in UK Law

Introduction

The grounds for judicial review in UK law were classified by Lord Diplock in the GCHQ case (Council of Civil Service Unions v Minister for the Civil Service (1985)) as illegality, irrationality, and procedural impropriety, with proportionality as a potential fourth ground. These grounds provide the doctrinal framework for the court’s supervision of administrative action.

Illegality

Illegality requires the decision-maker to understand correctly the law that regulates their decision-making power and to give effect to it. Illegality encompasses error of law, error of fact, fettering of discretion, improper purpose, and relevant and irrelevant considerations.

Irrationality

Irrationality (Wednesday unreasonableness) requires a decision that is so unreasonable that no reasonable authority could have come to it.

Procedural Impropriety

Procedural impropriety encompasses the rule against bias and the right to a fair hearing.

Proportionality

Proportionality requires that administrative action interfering with Convention rights be rationally connected to a legitimate aim, necessary, and fair.