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Judicial Review

Singapore Supreme Court Judicial Review & Prerogative Orders 2026

Complete guide to Supreme Court Judicial Review in Singapore. Explains Quashing Orders (Certiorari), Mandatory Orders (Mandamus), illegality, & procedural fairness.

Overview & Statutory Background

Judicial review is the constitutional mechanism whereby the Supreme Court of Singapore (General Division of the High Court and Court of Appeal) supervises the legality of administrative actions, statutory decisions, and executive orders. Under Order 24 of the Rules of Court 2021, individuals and corporations can apply for Prerogative Orders: Quashing Orders (Certiorari - invalidating illegal decisions), Mandatory Orders (Mandamus - compelling statutory duties), and Prohibition Orders (preventing unlawful actions). Grounded in fundamental public law principles, judicial review claims evaluate Illegality (ultra vires), Irrationality (*Wednesbury* unreasonableness), Procedural Impropriety (breach of natural justice), and Constitutional Breach. Use this guide to understand Singapore public law remedies.

Key Pass Highlights & Statutory Criteria

Supervisory Court

Supreme Court High Court

Verified

Governing Rule

Rules of Court Order 24

Verified

Key Remedies

Quashing, Mandatory, Prohibition

Verified

Public Law Grounds

Illegality, Irrationality, Fairness

Verified

Evaluation Criteria & Points Breakdown

Ground 1: Illegality (Ultra Vires Doctrine)

Illegality

Public authority acted outside statutory jurisdiction, misconstrued legal powers, or took into account irrelevant considerations.

Ground 2: Irrationality (Wednesbury Unreasonableness)

Irrationality

Decision was so outrageous in defiance of logic or accepted moral standards that no sensible authority could have made it.

Ground 3: Procedural Impropriety (Natural Justice)

Natural Justice

Breach of fundamental procedural fairness: failure to give fair hearing (*audi alteram partem*) or presence of bias (*nemo iudex in causa sua*).

Prerogative Remedies (Order 24)

Court Orders

Quashing Order (annuls illegal act), Mandatory Order (commands performance of statutory duty), & Prohibition Order (prevents future illegal act).

Mandatory Eligibility Requirements

Applicant must possess 'sufficient interest' (locus standi) in the matter (*Tan Eng Hong v AG*).

Application for leave must be filed within 3 months of the challenged decision date.

Target decision must be a public law exercise of statutory power (private contracts/arbitration excluded).

Heard exclusively in the General Division of the High Court.

Step-by-Step Application & Issuance Process

Stage 1: Ex-Parte Application for Leave to Apply

Applicant files leave application in High Court within 3-month statutory window.

High Court Prima Facie Leave Determination

High Court judge reviews papers to ensure claim is not frivolous and applicant has locus standi.

Stage 2: Substantive Inter-Partes Hearing

If leave granted, full inter-partes hearing conducted with Attorney-General's Chambers (AGC) representing state.

High Court Judgment & Prerogative Order Issuance

High Court issues binding Quashing Order, Mandatory Order, or Declaration of Unconstitutionality.

Court of Appeal Appeal Hearing

Either party appeals High Court ruling to Court of Appeal for final unappealable public law precedent.

Required Document Checklist

•Supreme Court Ex-Parte Application for Leave for Judicial Review (Order 24)

•Affidavit of Applicant detailing facts and public law illegality grounds

•Copy of Decision / Government Gazette Notice / Statutory Refusal Letter

•Draft Quashing Order / Mandatory Order / Prohibition Order

•Written Submissions on Locus Standi and Prima Facie Case

Frequently Asked Questions (FAQ)

Judicial Review is the court process by which the Supreme Court of Singapore reviews the legal validity of decisions made by government ministers, statutory boards, or public bodies.

A Quashing Order is a prerogative order issued by the High Court that quashes (invalidates and sets aside) an illegal or unconstitutional decision made by a public authority.

A Mandatory Order commands a public authority or government official to perform a mandatory statutory duty that they have unlawfully failed or refused to perform.

The primary grounds are: (1) Illegality (acting beyond legal powers), (2) Irrationality (Wednesbury unreasonableness), (3) Procedural Impropriety (breach of natural justice/fairness), and (4) Unconstitutionality.

Under Order 24 of the Rules of Court, an application for leave to apply for judicial review must be filed promptly and in any event within 3 months from the date of the decision.

Locus Standi requires that an applicant have a real, personal, or public interest in the subject matter to bring a judicial review application before the court (*Tan Eng Hong v AG*).