The failure of a public authority to take into account relevant considerations and the taking of irrelevant ones into account are grounds of judicial review in Singapore administrative law. They are regarded as forms of illegality.

If, in the exercise of its discretion on a public duty, an authority takes into account considerations which the courts consider not to be proper, then in the eyes of the law it has not exercised its discretion legally. On the other hand, considerations that are relevant to a public authority's decision are of two kinds: there are mandatory relevant considerations (that is, considerations that the statute empowering the authority expressly or impliedly identifies as those that must be taken into account), and discretionary relevant considerations (those which the authority may take into account if it regards them as appropriate). If a decision-maker has determined that a particular consideration is relevant to its decision, it is entitled to attribute to it whatever weight it thinks fit, and the courts will not interfere unless it has acted in a Wednesbury-unreasonable manner. This is consistent with the principle that the courts are generally only concerned with the legality of decisions and not their merits.

In the United Kingdom, it has been suggested that if the court interprets a statute to impose a duty on a public authority, the resources available to the authority are irrelevant to deciding how the duty should be carried out. Conversely, if the court interprets a statute to confer a discretionary power on a public authority, then resources are a relevant consideration. Also, public authorities are not required to take into account people's fundamental rights arising under the Human Rights Act 1998 as relevant considerations before arriving at decisions. Their only responsibility is to ensure that the decision itself complies with the European Convention on Human Rights. At present, there are no Singapore cases on these issues.

Introduction Administrative law is the area of law concerning the control of powers exercised by the government. It functions to regulate decision-making processes by public authorities with regard to maintaining basic standards of fairness and legality.. Administrative law in Singapore originates from and shares many similarities with administrative law in the United Kingdom. In general, claims for judicial review in administrative law fall under three broad categories – illegality, irrationality and procedural impropriety. Instances of illegality fall under two main headings: whether the authority was empowered to make the decision in question, and whether it properly exercised its discretion to make that decision. Grounds for illegality under the first heading include simple ultra vires, and errors as to precedent facts. The second heading includes grounds of judicial review such as making decisions on the basis of insufficient evidence or errors of material fact, failing to take into account relevant considerations and taking into account irrelevant ones, making decisions for improper purposes, fettering of discretion, and failing to fulfil legitimate expectations.Leyland & Anthony, "Illegality I", pp. 237–257; Leyland & Anthony, "Illegality II", pp. 258–277.

While a public authority may have fulfilled the legal and factual conditions required in order to properly exercise its statutory power, it may be deemed to have acted illegally if it makes its decision in a manner that contravenes administrative law rules. Under this category of judicial review, the courts' basic approach is to inquire if a decision-maker has taken into account all relevant considerations that it is required to take into account, and disregarded the irrelevant ones in making its decision. If it is satisfied that the decision-maker has done so, then the decision will stand, subject to other administrative law rules having been satisfied. The emphasis here is not on the body's decision itself, but on certain aspects of the reasoning process by which the decision was reached. Such an approach is consistent with the fundamental idea of judicial review that courts should not be concerned about the merits of a decision, but instead, only with its legality.Leyland & Anthony, "Illegality I", p. 247.

Three categories of considerations

In the United Kingdom, the law on relevant and irrelevant considerations was explained in R. v. Somerset County Council, ex parte Fewings (1995).. In this case, the applicants applied for judicial review of the legality of a ban on stag hunting on the basis that the Somerset County Council had taken into account an irrelevant consideration – the morality of stag hunting – when making its decision. In his dissenting judgment, Lord Justice of Appeal Simon Brown identified three categories of considerations that decision-makers need to be aware of:Ex parte Fewings, pp. 1049–1050.

those clearly (whether expressly or impliedly) identified by the statute as considerations to which regard must be had; those clearly identified by the statute as considerations which must not be had; and those to which the decision-maker may have regard if in his judgment and discretion he thinks it right to do so.

Lord Justice Brown elaborated that for the third category, there is "a margin of appreciation within which the decision-maker may decide just what considerations should play a part in his reasoning process", subject to Wednesbury unreasonableness.

The Singapore case of City Developments Ltd. v. Chief Assessor (2008). illustrates a similar point. The Court of Appeal stated that "[w]here a wide range of considerations needs to be taken into account or a power is conferred on an authority exercisable on the authority's 'satisfaction', the courts are reluctant to intervene in the absence of bad faith or capriciousness". It was also said that "[w]hat is or is not a relevant consideration will depend on the statutory context."City Developments, p. 159, para. 17.

Taking into account irrelevant considerations The decision of an administrative body is subject to judicial review if it took into account irrelevant considerations. If, in the exercise of its discretion on a public duty, the body takes into account considerations which the courts consider not to be proper, then in the eyes of the law it has not exercised its discretion legally..

In the United Kingdom, a seminal case applying this principle is R. v. Secretary of State for the Home Department, ex parte Venables (1997).. In this case, the Home Secretary had taken into account public opinion when deciding upon the tariff of 15 years for holding in custody two boys detained at Her Majesty's pleasure for having murdered James Bulger, a two-year-old child, when they were both ten years old. Lord Steyn held that the public petitions considered were worthless and incapable of informing the Home Secretary in a meaningful way of the true state of public opinion in respect of the tariff. Hence, the reliance on the public petition in coming up with its decision was an irrelevant consideration which justified the setting-aside of the Home Secretary's decision.Ex parte Venables, pp. 524–526.

R. v. Ealing London Borough Council, ex parte Times Newspapers Ltd. (1986)R. v. Ealing London Borough Council, ex parte Times Newspapers Ltd. (1986) 85 L.G.R. [Local Government Reports] 316, Divisional Court (England and Wales). dealt with the principle of irrelevant considerations as well. In this case, Ealing London Borough Council had refused to provide certain newspapers in their public libraries because the newspapers' proprietors were political rivals of members of the Council. The Divisional Court of England and Wales held that the political sentiments of the local authority should not have interfered with its decision to run the public libraries because it was irrelevant to its statutory duty to provide "a comprehensive and efficient library service for all persons desiring to make use thereof".Public Libraries and Museums Act 1964 (c. 75, UK), s. 7(1): see Ex parte Times Newspapers Ltd., p. 326.

This legal principle has not been examined extensively in Singapore but it can be regarded to have been applied in Tan Gek Neo Jessie v. Minister for Finance (1991).Tan Gek Neo Jessie v. Minister for Finance 1 S.L.R.(R.) 1, High Court (Singapore). The plaintiff was told by the Registrar of Businesses to change the name of her business "J. C. Penney Collections" to one which did not resemble the name "J. C. Penney". This was because the Registry of Trade Marks already had two trademarks registered with it with the name "Penneys" at that time. The proprietor of both the trademarks was J. C. Penney Company Inc., an American corporation. The Minister for Finance and the Registrar alleged that the plaintiff had used this business name to ride on the reputation of the American corporation by misleading Singaporeans into thinking that her business was associated with the American corporation. Both administrative bodies held that the mere resemblance of the names was proof of this. This was eventually held to be an irrelevant consideration as neither of the trademarks had been used by the American corporation to identify retail services in Singapore. Thus, it had no business reputation in Singapore in relation to the name "J. C. Penney". Furthermore, there was no evidence to suggest that the plaintiff, at the time of registering her business, was aware of the existence of the two registered trademarks. In arriving at the decisions to order the plaintiff to change her business name and to dismiss her appeal against that order, the Registrar and the Minister had respectively taken into account an irrelevant consideration. Ultimately, the court made an order of certiorari (now known as a quashing order) to quash both decisions.Tan Gek Neo Jessie, pp. 8–13, paras. 16–29.

Lines International Holding (S) Pte. Ltd. v. Singapore Tourist Promotion Board (1997)Lines International Holding (S) Pte. Ltd. v. Singapore Tourist Promotion Board 1 S.L.R.(R.) 52, H.C. (Singapore). is another local case in which the principle of irrelevant considerations was raised. The Port of Singapore Authority (PSA), which was responsible for promoting the use, improvement and development of Singapore's ports, had introduced a policy of not allocating berths at the Singapore Cruise Centre to cruise ships unless over a three-month period 30% or fewer of the cruises in a cruise operator's schedule consisted of "cruises-to-nowhere". Such cruises, which left Singapore's territorial waters and returned to Singapore without calling at any other destination port, tended to be mainly for gambling purposes.Lines International, p. 58, para. 5. The plaintiffs argued that in developing this policy, the PSA had assumed that gambling by Singaporeans in international waters was an unlawful activity. As there was no proper legal basis for this assumption, it was an irrelevant consideration which had seriously tainted the formulation of the policy. The High Court denied that this was the case, and found that the main consideration had been whether the development of the cruise industry would be impeded if Singapore gained an undesirable reputation as a hub for gambling cruises. The alleged irrelevant consideration had not been the substantial reason for the ultimate decision.Lines International, pp. 82–84, paras. 86–91.

Failing to take into account relevant considerations