The remedies available in Singapore administrative law are the prerogative orders – the mandatory order (formerly known as mandamus), prohibiting order (prohibition), quashing order (certiorari), and order for review of detention (habeas corpus) – and the declaration, a form of equitable remedy. In Singapore, administrative law is the branch of law that enables a person to challenge an exercise of power by the executive branch of the Government. The challenge is carried out by applying to the High Court for judicial review. The Court's power to review a law or an official act of a government official is part of its supervisory jurisdiction, and at its fullest may involve quashing an action or decision and ordering that it be redone or remade.

A mandatory order is an order of the High Court commanding a public authority to perform a public duty, while a prohibiting order operates to prevent illegal action by an authority from occurring in the first place. A quashing order, the most commonly sought prerogative order, has the effect of invalidating an ultra vires decision made by an authority. Obtaining a mandatory, prohibiting or quashing order is a two-stage process, as an applicant must be granted leave by the Court to apply for the order. The Court must find the existence of a proper public law issue and available grounds of review. Leave will be granted provided that an arguable and prima facie case of reasonable suspicion that the authority has acted in breach of administrative law rules is established.

An order for review of detention directs someone holding a person in detention to produce the detainee before the High Court so that the legality of the detention can be established. The power of the Court to require that this be done is specifically mentioned in Article 9(2) of the Constitution of Singapore. While the other prerogative orders may only be applied for with the court's permission, an order for review of detention may be applied for without prior permission from the court.

A declaration is a pronouncement by a court stating the legal position between the parties to an action, based on the facts that have been presented to the court. Before 1 May 2011, it was not possible to apply for prerogative orders and declarations in the same set of legal proceedings. Following that date, changes to Order 53 of the Rules of Court permitted an application for a declaration to be made together with an application for one or more prerogative orders. However, the application for a declaration cannot be made unless the court grants leave for the prerogative orders to be applied for.

The Government Proceedings Act bars the High Court from granting injunctions against the Government or one of its officers. An injunction is an equitable private law remedy that restrains a public authority from doing an act that is wrongful or ultra vires. In place of an injunction, the Court may make a declaration concerning the parties' rights. At common law, there is no general right to claim damages – that is, monetary compensation – if rules of public law have been breached by an authority. In order to obtain damages, an aggrieved person must be able to establish a private law claim in contract or tort law.

Introduction

Supervisory jurisdiction of the High Court The aim of administrative law is to regulate the executive government by providing remedies which individuals can apply for when challenging administrative actions and decisions, and failures to take action and make decisions. Where the exercise of statutory or other discretionary power by public authorities contravenes the Constitution or is unlawful under administrative law, various remedies may be available when a judicial review action is taken.

Judicial review, the means by which the High Court controls the exercise of legislative and executive power, is part of the Court's supervisory jurisdiction. The basis of this jurisdiction was affirmed by the Court of Appeal in Ng Chye Huey v. Public Prosecutor (2007). as inherent in nature, that is, deriving from the common law rather than statute., cited in Haron bin Mundir v. Singapore Amateur Athletic Association 2 S.L.R.(R.) 494 at 500–501, para. 18, High Court (Singapore) and in Ng Chye Huey, p. 130, para. 48. The Court noted that this jurisdiction had "existed historically at common law" and "is still very much a part of our judicial system".Ng Chye Huey, p. 134, para. 53. The inherent power of the High Court to review the decisions of inferior courts and other administrative bodies does not, however, extend to co-ordinate bodies. In other words, one High Court judge may not exercise judicial review over a decision by another High Court judge.Ramalingam Ravinthran v. Attorney-General 4 S.L.R. 196 at 200–201, paras. 6–7, H.C. (Singapore), citing . In addition, there are no provisions in the Supreme Court of Judicature Act ("SCJA"). which confer on the Court of Appeal the power to exercise supervisory jurisdiction over the High Court or – as pointed out in Ng Chye Huey – the Subordinate Courts.Ng Chye Huey, p. 138, para 63.

The effective scope of the principles of judicial review depends on how the Court chooses to exercise its discretion in pursuance of its supervisory jurisdiction.

Remedies The remedies available in a judicial review action are the prerogative orders – the mandatory order (formerly known as mandamus), prohibiting order (prohibition), quashing order (certiorari), and order for review of detention (habeas corpus) – and the declaration, a form of equitable remedy. All these remedies that the High Court may grant are discretionary. A successful claimant has no absolute right to a remedy. In deciding whether to grant a remedy, the Court will take into account factors such as the following:.

any prejudicial delay by the claimant in bringing the case; whether the claimant has suffered substantial hardship; any impact the remedy may have on third parties; whether a remedy will have any practical effect, or whether the matter has become academic (in which case a remedy will usually not be granted); the merits of the case; and whether the remedy will promote good administration.

Prerogative orders The ancient remedies of certiorari, mandamus, prohibition and habeas corpus were originally only available to the British Crown and thus termed prerogative writs, that is, writs that could be issued at the prerogative of the sovereign..See also : "Writs, not ministerially directed, (sometimes called prerogative writs, because they are supposed to issue on the part of the King,) such as writs of mandamus, prohibition, habeas corpus, certiorari ... upon a proper case, they may issue to every dominion of the Crown of England. There is no doubt as to the power of this Court; where the place is under the subjection of the Crown of England; the only question is, as to the propriety." By the end of the 16th century, they could theoretically be sought by any aggrieved citizen. In 1938, the writs were abolished in the United Kingdom and replaced by prerogative orders with essentially the same names and functions.. As a former British colony, Singapore inherited English administrative law at independence and the Singapore courts continue to pay close attention to English cases. In Singapore, the prerogative orders were known by their traditional names until 2006, when the names were modernised.By the , ss. 2 and 6 and the 4th Sch., in force on 1 January 2006. Section 2 of the Act inserted s. 41B into the , which requires the prerogative orders to be referred to by their modern names in all written laws.

Following the change, paragraph 1 of the First Schedule to the Supreme Court of Judicature Act, which is entitled "Prerogative orders", now states that the High Court possesses the following power:SCJA, s. 18(1), states: "The High Court shall have such powers as are vested in it by any written law for the time being in force in Singapore." Section 18(2) continues: "Without prejudice to the generality of subsection (1), the High Court shall have the powers set out in the First Schedule."

The Subordinate Courts are not empowered to grant prerogative orders. ("SCA"), s. 19(3)(b): "[A] District Court's jurisdiction ... shall not include — (a) any supervisory jurisdiction or revisionary jurisdiction; (b) any jurisdiction relating to the judicial review of any act done or decision made by any person or authority, including the issue of any of the following prerogative orders: (i) a Mandatory Order; (ii) a Prohibiting Order; (iii) a Quashing Order; (iv) an Order for Review of Detention ...".SCA, s. 52(1A)(a): "The jurisdiction of a Magistrate's Court ... shall not include jurisdiction to hear and try any action where — (a) there is no claim for any sum of money ...".See also the Rules of Court (Cap. 322, R 5, 2006 Rev. Ed. ) ("ROC"), Order 53, rule 8, which states: "This Order is not applicable to the Subordinate Courts."

The amendment of the provision removed a specific reference to the High Court's power to issue writs of quo warranto,Prior to the amendment taking effect in 2006, para. 1 of the 1st Sch. to the SCJA stated that the High Court had "[p]ower to issue to any person or authority directions, orders or writs, including writs of the nature of habeas corpus, mandamus, prohibition, quo warranto and certiorari, or any others, for the enforcement of any of the rights conferred by any written law or for any purpose". a remedy used to challenge a person's right to hold public office. There are no reported cases of quo warranto having been issued in Singapore. Since paragraph 1 still empowers the High Court "to issue to any person or authority any ... order or writ for the enforcement of any right conferred by any written law or for any other purpose", it may be that the Court's power to issue an order equivalent to a quo warranto has not been impaired.

Mandatory orders A mandatory order is an order of the High Court which commands a public body to perform a public duty, and is usually employed to compel public bodies to exercise the powers given to them. It may be used in combination with another remedy, most commonly a quashing order. In such a case, the quashing order will set aside the unlawful decision, and the mandatory order will require the public body to reconsider the matter.. A person who complies with a mandatory order cannot have legal proceedings taken against him or her for doing so.ROC, O. 53, r. 6(1).

Since it is the responsibility of the High Court to determine the legality of a decision rather than its merits,. it will not order a public body to take a certain course of action, but will merely enjoin it to perform its duty in a lawful manner. In R. v. Justices of Kingston, ex parte Davey (1902),R. v. Justices of Kingston, ex parte Davey (1902) 86 L.T. 589 at 591, applied in Re San Development Co's Application [1971–1973] S.L.R.(R.) 203 at 207, para. 15, H.C. (Singapore); and Borissik v. Urban Redevelopment Authority at 4 S.L.R. 92 at 98, para. 21, H.C. (Singapore). it was held: