Grounds for Judicial Review in Ireland Explained

“The decision is wrong” is not a ground of judicial review. “The decision was reached without hearing me, for reasons never stated, under a power the statute does not confer” — that is three. The craft of public law is translating injustice into the recognised categories. Here they are.

1. Acting Outside Powers (Ultra Vires) and Error of Law

Public bodies possess only the powers statute gives them. A condition imposed that the Act never authorised, a sanction beyond the scale, a test applied from the wrong section — each invalidates the decision regardless of its merits. These grounds are won and lost in the statutory text, which is why the first document a solicitor opens is the Act, not the decision letter.

2. Breach of Fair Procedures

Constitutional justice imposes two ancient rules: audi alteram partem — hear the other side — and nemo iudex in causa sua — no one judges their own cause. In practice: notice of the case against you, disclosure of the material relied on, a genuine opportunity to respond, and an objectively unbiased decision-maker. The intensity scales with the stakes — a livelihood-ending decision demands more process than a routine one. Deep dive: fair procedures and natural justice.

3. Failure to Give Reasons

Modern Irish law — anchored by the Supreme Court’s Mallak line of authority — requires decision-makers to give reasons adequate to let the affected person know why they lost and whether the decision is lawfully challengeable. Template refusals reciting statutory formulas are the most commonly vulnerable decisions in the system. Full guide: the reasons ground.

4. Irrationality and Proportionality

A decision so unreasonable that no rational decision-maker could have reached it is invalid — a deliberately demanding standard. Where fundamental rights are engaged, proportionality asks a sharper question: does the measure impair rights more than its legitimate purpose requires? These grounds succeed rarely but matter enormously when they do.

5. Legitimate Expectation

Where a public body, by promise or settled practice, led you to expect a benefit or procedure, and reversing course would be unjust, the courts can hold it to its word — within limits (no expectation can override statute). The doctrine explained: legitimate expectation in Irish law.

6. Relevant and Irrelevant Considerations, Fettered Discretion

The decision-maker must weigh what the law requires and exclude what it prohibits — and must actually exercise the discretion conferred rather than applying an internal blanket policy as if it were law. “We never grant X” is frequently the sound of a ground of review being created.