Exclusion of judicial review has been attempted by the Parliament of Singapore to protect the exercise of executive power. Typically, this has been done though the insertion of finality or total ouster clauses into Acts of Parliament, or by wording powers conferred by Acts on decision-makers subjectively. Finality clauses are generally viewed restrictively by courts in the United Kingdom. The courts there have taken the view that such clauses are, subject to some exceptions, not effective in denying or restricting the extent to which the courts are able to exercise judicial review. In contrast, Singapore cases suggest that ouster clauses cannot prevent the High Court from exercising supervisory jurisdiction over the exercise of executive power where authorities have committed jurisdictional errors of law, but are effective against non-jurisdictional errors of law.

A partial ouster or time limit clause specifies a restricted period, after which no remedy will be available. Such clauses are generally effective, unless the public authority has acted in bad faith. Similarly, the existence of bad faith entitles applicants to challenge decisions of authorities despite the existence of statutory provisions declaring such decisions to be conclusive evidence of certain facts. In the absence of bad faith, the courts will enforce conclusive evidence clauses.

In general, subjectively worded powers are also viewed restrictively by the Singapore courts. In Chng Suan Tze v. Minister for Home Affairs (1988), the Court of Appeal took the view that an objective test applied to the exercise of discretion conferred by the ("ISA") on the President and the Minister for Home Affairs concerning the detention without trial of persons thought to be a risk to national security. Hence, the jurisdiction of the High Court was not completely ousted, and it could objectively examine whether the relevant decision-makers had exercised their powers properly. However, legislative amendments to the ISA in 1989 reversed the effect of Chng Suan Tze by mandating that the courts are to apply a subjective test to the exercise of the discretion, and by excluding judicial review except where there is doubt whether the procedures set out in the Act were adhered to. Nevertheless, the subjective test is only applicable in the context of the ISA, and the rule that an objective test applies to subjectively worded powers continues to apply where statutes other than the ISA are concerned.

Total ouster or finality clauses

An ouster clause in a statute is an attempt by the legislature to prevent an act or decision by a public authority from being challenged before the courts. Such clauses thus serve as a signal to decision-makers that they may operate without fear of intervention by the courts at a later stage. One common kind of ouster clause is the total ouster or finality clause, which is inserted into a statute to indicate that the decision of a particular judge or tribunal is final and cannot be challenged by any court..

The main legal issue with ouster clauses is whether it is in fact possible to exclude the jurisdiction of the courts by the use of carefully drafted provisions. Thio Li-ann has noted that "courts generally loathe ouster clauses as these contradict the rule of law whereby judges finally declare the legal limits of power and also as the individual's ultimate recourse to the law is denied. Hence, courts try to construe these strictly to minimise their impact. In so doing, they may be going against the grain of parliamentary will.".

Ouster clauses are related to another administrative law concept: jurisdictional and non-jurisdictional errors of law. Traditionally, at common law, an ouster clause precludes a court from interfering with a decision made by a public authority which was acting within its jurisdiction, but committed a non-jurisdictional error of law. However, the clause is not effective in preventing judicial review of errors of law that affect the jurisdiction of the authority to make the decision.. For instance, in R. v. Medical Appeal Tribunal, ex parte Gilmore (1957),. Lord Justice of Appeal Alfred Denning said that it was "well settled that the remedy by certiorari is never to be taken away by any statute except by the most clear and explicit words. The word 'final' is not enough."Ex parte Gilmore, p. 583. The effect of such a clause is to make "the decision final on the facts, but not final on the law. Notwithstanding that the decision is by a statute made 'final,' certiorari can still issue for excess of jurisdiction or for error of law on the face of the record."Applied in . However, in the light of developments in the law, such a differentiation may no longer be applicable depending on the judicial school of thought employed.

UK position General rule The starting point for analysing ouster clauses and their effects is the landmark decision Anisminic Ltd. v. Foreign Compensation Commission (1968).. In that case, the House of Lords is regarded as having abolished the distinction between jurisdictional and non-jurisdictional errors of law when it was considering the effect of an ouster clause. In Anisminic, their Lordships were faced with a provision which stated that "the determination by the Commission of any application made to them under this Act shall not be called in question in any court of law".Foreign Compensation Act 1950 (14 Geo. 6. c. 12 (UK)), s. 4(4). In his judgment, Lord Reid differentiated between the arguments put forth by the parties. He held that while the respondents had argued that the provision clearly denied the court the ability to question the determination made by the Foreign Compensation Commission, the question at hand did not even involve the questioning of the purported determination and instead focused on whether there was in fact a valid determination. He pointed out that "if you seek to show that a determination is a nullity you are not questioning the purported determination – you are maintaining that it does not exist as a determination".Anisminic, p. 170. He then held it was a well-established principle that a provision ousting the ordinary jurisdiction of the court must be construed strictly – if such a provision is reasonably capable of having two meanings, the meaning which preserves the ordinary jurisdiction of the court should be taken. If Parliament had intended to introduce a new kind of ouster clause that would protect such nullities from being questioned, better drafting of the provision would be required.

In his judgment, Lord Reid also took the opportunity to deal with the issue of jurisdictional and non-jurisdictional errors of law. While recognising the traditional understanding that jurisdictional errors of law are of no effect, his Lordship also stated that there are many cases where although the decision-maker has jurisdiction to decide, the determination is also a nullity. He then gave a non-exhaustive list of these cases:Anisminic, p. 171.

The decision-maker may have given its decision in bad faith. It may have made a decision which it had no power to make. It may have failed in the course of the inquiry to comply with the requirements of natural justice. It may, in perfect good faith, have misconstrued the provisions giving it power to act so that it failed to deal with the question remitted to it and decided some question which was not remitted to it. It may have refused to take into account something which it was required to take into account. It may have based its decision on some matter which, under the legal provisions establishing the decision-maker, it had no right to take into account.

However, what is of significance is that his Lordship did not expressly reject the effectiveness of such ouster clauses where the decision is valid. He recognised that "[u]ndoubtedly such a provision protects every determination which is not a nullity". Peter Cane has written that Lord Reid thus affirmed that "the ouster clause in question would be effective to prevent the award of a judicial review remedy only if the error of law was within jurisdiction". However, it appears that Anisminic had defined the concept of jurisdictional error of law so broadly that it had made redundant the old divide between jurisdictional and non-jurisdictional errors and had "led to the use of the word 'jurisdictional' in a wide sense to cover all errors of law which entailed illegality".Cane, p. 240. The judgment thus had the effect of reducing the effect of statutory ouster clauses and expanding the limits of judicial review.Cane, p. 241.

Later cases have treated Anisminic as implying that any action committed in error by an administrative agency or body is deemed to affect the jurisdiction of the body to carry out the action, and hence is reviewable by a court of law despite the ouster clause. The blurred distinction between jurisdictional and non-jurisdictional errors of law was recognised and discussed in R. v. Lord President of the Privy Council, ex parte Page (1992).. The House of Lords reviewed the development of general principles of judicial review since Anisminic and concluded that the courts will intervene to ensure that the powers of public decision-making bodies are exercised lawfully. In his judgment, Lord Browne-Wilkinson referred to O'Reilly v. Mackman (1983). and opined that "the decision in [Anisminic] rendered obsolete the distinction between errors of law on the face of the record and other errors of law by extending the doctrine of ultra vires."Ex parte Page, p. 701. Thus, an ouster clause is ineffective when the decision-maker has acted unlawfully, whether the unlawfulness is jurisdictional or non-jurisdictional in nature. This is because "Parliament had only conferred the decision-making power on the basis that it was to be exercised on the correct legal basis: a misdirection in law in making the decision therefore rendered the decision ultra vires".

The issue was revisited in the subsequent case of R. (on the application of Cart) v. Upper Tribunal (2011).. The Supreme Court of the United Kingdom disapproved of certain pronouncements by the lower courts which appeared to signal a return to the pre-Anisminic position.The pronouncements were summarized by Lord Dyson in Cart, p. 141, para. 108. According to Lord Dyson, this was not justified as "the importance of Anisminic is that it showed that a material error of law renders a decision a 'nullity' so that the decision is in principle judicially reviewable".Cart, p. 142, para. 110. He went on to state that "as a matter of principle, there is no justification for drawing the line at jurisdictional error". In his opinion, any restrictions on judicial review require justification and, prima facie, such review should be available to challenge the legality of decisions of public bodies.Cart, p. 145, para. 122.

Exceptions Decisions under domestic laws; court decisions Despite the extensiveness of the ruling in Anisminic, it appears that there may be instances where the courts will still be bound by the jurisdictional and non-jurisdictional error of law divide. Cane has noted that there are three views. The first is that the distinction between jurisdictional and non-jurisdictional errors of law is still relevant, while the second is that all errors of law go to jurisdiction. The third view takes a middle ground that allows for certain exceptions to the approach in the second view.