Prospective Overruling in Singapore: A Judicial Framework for the Future?

© Springer International Publishing Switzerland 2015
Eva SteinerComparing the Prospective Effect of Judicial Rulings Across JurisdictionsIus Comparatum – Global Studies in Comparative Law310.1007/978-3-319-16175-4_16

16. Prospective Overruling in Singapore: A Judicial Framework for the Future?

Gary K. Y. Chan 

School of Law, Singapore Management University, 60 Stamford Road Level 4, Singapore, 178900, Singapore



Gary K. Y. Chan


The doctrine of prospective overruling has been applied in Singapore since the 1990s with a focus on the applicability of nullen crimen nulla poena sine lege embodied in the Singapore Constitution. The underlying objectives are to maintain fairness to the accused persons and to protect their legitimate expectations in criminal cases. The recent landmark decision in Public Prosecutor v Hue An Li has extended the applicability of the doctrine beyond criminal cases to also include civil matters. Though the general default position is that judicial pronouncements apply retrospectively and prospectively, the High Court has indicated that judges may exercise their discretion to limit the retroactive effect of such judicial pronouncements. It has developed a framework comprising a few factors for determining if prospective overruling should be invoked in a given case. The factors include the extent of the entrenchment of the existing rule or principle, the extent of change of the law, the reliance on the existing law and the level of foreseeability of the legal change. This judicial framework points the way forward for prospective overruling in Singapore and, at the same time, allows some flexibility for judicial identification and weighing of the specific factors according to the facts of the case.

Prospective overrulingStare decisisDeclaratory theoryLegitimate expectationsSingapore nullen crimen nulla poena sine lege


The development of the common law in Singapore has progressed steadily since her founding in 1819 and, thereafter, her independence in 1965. During this period, English common law and equity have been received into Singapore subject to local circumstances. The process of autochthonous common law development gathered significant momentum when the Singapore Court of Appeal assumed its premier position in the judicial hierarchy in 1994 following the abolition of appeals to the Privy Council sitting in London.1 The enactment of the Application of English Law Act 19942 (“AELA”) and the issuance of the Practice Statement on Judicial Precedent in the same year served as catalysts for the indigenous development of Singapore common law. Together with the significant constitutional amendments and legislative activity in Parliament, the Singapore legal institutions and law advanced rapidly in tandem with societal changes.

Amidst the legislative buzz and the autochthonous jurisprudence that was taking shape in Singapore, an important development, in the form of the doctrine of prospective overruling, was waiting in the wings. Judicial scrutiny of the doctrine of prospective overruling is a relatively new phenomenon in Singapore dating back only to the 1990s. At that time, the interest and significance in prospective overruling was primarily fueled by criminal cases involving the life and liberty of accused persons and the constitutional principle founded on the concept of nullen crimen nulla poena sine lege (that one cannot be punished for doing something that is not prohibited by law). Several questions confronted the courts: when courts have decided to overrule an existing rule or principle in criminal cases, should they only apply the new rule or principle prospectively? What is the impact of the Singapore Constitution (in particular Article 11) on prospective overruling in criminal cases? Could prospective overruling also apply to an existing practice as opposed to a legal rule or principle? As we will see below, these questions were examined with certain overriding objectives in mind, namely to ensure fairness to the accused persons and to protect their legitimate expectations in criminal cases.

It was only in 2014 that the Singapore High Court in a landmark decision, Public Prosecutor v Hue An Li,3 extended the doctrine to both criminal and civil cases. It also examined the arguments for and against prospective overruling and developed a general framework to ascertain the appropriate circumstances in which prospective overruling may be invoked in a given case. At the heart of the debate concerning prospective overruling is the maintenance of the rule of law, the intertwined issues of ensuring certainty (of which legitimate expectations is an important part) as well as flexibility in the law and the goals of achieving fairness and justice for the litigants.

I will begin with a brief historical background to the development of the common law in Singapore in “Historical Background to the Common Law in Singapore”, followed by a discussion in “Doctrine of Stare Decisis and the Rejection of the Declaratory Theory in Singapore” on the principles of stare decisis and the rejection of the declaratory theory in Singapore. In “Prospective Overruling in Singapore: The Approach in Public Prosecutor v Hue An Li, I examine the doctrine of prospective overruling as applied in Singapore by reference to Public Prosecutor v Hue An Li. “Criminal Cases and Article 11 of the Constitution” focuses on the application of Article 11 of the Singapore Constitution based on the principle of nullen crimen nulla poena sine lege to the criminal cases decided in the 1990s whilst  “Constitutional Invalidation of Statutes and Prospective Overruling” discusses the relationship between the doctrine of prospective overruling and the constitutional invalidity of statutes.

Historical Background to the Common Law in Singapore

The system of stare decisis in Singapore cannot be fully appreciated without at least a brief historical background on the reception of English common law into Singapore. Her British colonial legacy began when Sir Thomas Stamford Raffles of the East India Company and Lieutenant-Governor of Bencoolen founded Singapore in 1819. After a period of “legal chaos” between 1819 and 1826 in which no uniform law applied to the colony (Phang 2006: 1–4), English law was received into Singapore with the promulgation of the Second Charter of Justice on 27 November 1826.4 The case of R v Willans 5 is regarded to have introduced English law as of November 1826 into Singapore via the Second Charter. This general reception of English law, whether English statutes or common law as at 27 November 1826, into Singapore was subject to local conditions and circumstances (Phang 1986).

In 1878, section 5 of the Civil Law Ordinance and subsequently, the Civil Law Act6 provided for the specific and continuous reception of English mercantile law into Singapore. If a question or issue arose in Singapore with respect to specified categories of law or with respect to mercantile law generally, the law to be administered was to be the same as that administered in England at the corresponding period subject to other provision made by any law having force in Singapore. Similar to the Second Charter, English law received under section 5 of the Civil Law Act may be modified to suit local circumstances.7 This provision generated various problems relating to the determination of when an ‘issue’ has arisen,8 the meaning of ‘mercantile law’, the extent to which English law was to be applied and other academic controversies.9 What was clear is that English law continued to be received into Singapore subject to suitability and modifications.

In 1993, the Singapore Parliament repealed section 5 of the Civil Law Act and enacted the AELA. The repeal put to rest the abovementioned difficulties ensuing from section 5 of the Civil Law Act. In its place, the AELA’s role was to preserve the reception of English law, namely English common law and equity as well as specific English statutes relating to commercial law. Section 3(1) of the AELA stipulates that “the common law of England (including the principles and rules of equity), so far as it was part of the law of Singapore immediately before the commencement of [the AELA i.e. 12 November 1993], shall continue to be part of the law of Singapore”. The corollary is that, subsequent to the above cut-off date, the “common law of Singapore would be the common law as declared and developed by [Singapore] courts”.10 The enactment of the AELA, together with the 1994 Practice Statement (Judicial Precedent) which will be discussed below, provided the impetus for the autochthonous development of the common law in Singapore.

In tandem with Singapore’s colonial legal history, it was not surprising that the reception of English common law was subject to the concepts of suitability and modifications which are dependent on the circumstances and conditions in Singapore.11 Insofar as English statutes are concerned, the AELA lists 13 English commercial statutes12 which would form part of Singapore law. Certain Imperial Acts13 passed by the UK Parliament from the colonial era were also made part of Singapore law.

Doctrine of Stare Decisis and the Rejection of the Declaratory Theory in Singapore

Judicial power is vested in the Singapore judiciary under the Constitution.14 This power is premised on the existence of a controversy between a State and its subjects or between two subjects and entails the court finding the facts, applying the law to the facts and determining the rights and obligations of the parties concerned.15 The judicial grounds of decisions ensuing from the resolution of the disputes form the bedrock of case precedents.

The doctrine of stare decisis or case precedents is primarily founded on respect for the judicial hierarchy, consistency and fairness of and certainty in the law (Woon 1999: 299). The Singapore judicial hierarchy places the Court of Appeal at the apex, followed by the High Court, District Court and Magistrates’ Court in that order. The decisions of the Singapore Court of Appeal bind all lower courts. However, a prior High Court decision is not legally binding on the High Court.16 The Singapore common law develops through the application of legal principles embodied in case precedents to the facts before the judge. The ratio decidendi of a prior court decision is binding on lower courts though the latter may legitimately refuse to follow a ratio decidendi in a prior precedent if the factual matrices are materially different.17 Obiter dicta, on the other hand, are not binding under the doctrine of stare decisis. The per incuriam rule grants courts some leeway to refuse to follow ratio decidendi in limited circumstances. The lower courts cannot invoke the per incuriam rule against the higher court.18 However, the Court of Appeal may invoke the per incuriam rule against its own prior decision.19

Where there are no relevant precedents that are directly on point, judges draw upon analogies to existing precedents in order to extend the law or create new law in order to resolve the dispute (Twining and Miers 2010: 349). At times, policy considerations are taken into account to create new law. Such a process is neither haphazard nor radical but is based on principled and incremental developments.20 As remarked by the Singapore Court of Appeal in a recent decision, “It is trite to state that the common law is incremental in nature: the doctrine of stare decisis obliges judges to adjudicate with reference to decided cases”.21 The reality is that judges do make law with reference to precedents, legal principles, extra-legal policies and a dose of pragmatism.22

To the extent that it is accepted that the common law rules and principles have existed from time immemorial and are merely declared rather than created by the judges, it is not likely that judges will propound a new rule or principle that overrules a prior precedent. In this connection, judges would probably not adopt the doctrine of prospective overruling if the consequence would be to highlight the divide between the old and the new common law rule or principle as of a certain arbitrary date.

In England, the House of Lords in Kleinwort Benson Ltd v Lincoln City Council 23 had rejected the declaratory theory of law. It was acknowledged that the common law changed from time to time in order to keep abreast with the times.24 In Public Prosecutor v Manogaran s/o R Ramu,25 a criminal case that will be relevant to our discussion on prospective overruling below, the Singapore Court of Appeal had also doubted the viability of the declaratory theory. This view was further reinforced by the same Court in Review Publishing Co Ltd v Lee Hsien Loong,26 a defamation case, in which the appellant (media defendant) argued that the Reynolds privilege27 in England had always been part of the common law applicable to Singapore. The argument did not find favour with the Court of Appeal:

Basically, the Declaratory Theory is not a principle of the common law in the same way that the doctrine of stare decisis and the doctrine of res judicata are principles of the common law. Instead, it is merely a theory or an explanation as to how the common law develops. It is a juridical method of expressing the idea that the common law has the capacity to provide the right answer (in the sense of doing justice) at any point in time vis-à-vis any legal issue by applying established principles (whether narrow or broad) as changing or changed social conditions require. In short, the Declaratory Theory lacks legal force, and is therefore neither a sufficient nor a satisfactory ground for contending that the Reynolds privilege is and has always been part of the traditional qualified privilege defence at common law.

Further, the Court was of the view that the declaratory theory is a “fiction”28 (McLachlin 2000: 317–318) and that the theory is “inapt to explain the evolution of common law principles that are based on policy considerations which change over time”.29 It added that as Reynolds was influenced by Article 10 of the European Convention for the Protection of Human Rights and Fundamental Freedoms and the UK Human Rights Act 1998, “the Reynolds privilege cannot possibly be said to have existed ‘from time immemorial’ ”.30

It is fair to say that the rejection of the declaratory theory, at the very least, removes one obstacle to the doctrine of prospective overruling. More will be said of this below but it suffices to note at this stage that the acknowledgement that judges do make law provides some leeway for them to overrule existing rules and principles in favour of applying a new rule or principle for the future. One concern that may arise is that unelected judges, when they are engaging in prospective overruling, appear to be acting as legislators.31 The danger of judicial usurpation of legislative powers is recognised but the common law would be much poorer if judges are prevented from changing and developing the existing rules and principles. That being said, judicial power for the development of the common law must be exercised within proper limits. In similar vein, if prospective overruling were to be applied, its scope should be kept within justifiable parameters. On that note, it is fitting that we turn to the recent Singapore High court decision on prospective overruling.

Prospective Overruling in Singapore: The Approach in Public Prosecutor v Hue An Li

When a judge pronounces a change in the law, the pronouncement normally operates both retrospectively and prospectively32 (i.e., it affects both the litigants before the court as well as potential litigants after the legal change). If pure prospective overruling were accepted as a general rule, however, the change in the law will only be applied prospectively (i.e., it will not affect the litigants before the court pronouncing on the legal change). Would this general position be desirable for the common law in Singapore? Prior to the landmark decision in Public Prosecutor v Hue An Li, Singapore had applied prospective overruling to two criminal cases33 with particular regard to Article 11 of the Singapore Constitution and the principle nullen crimen nulla poena sine lege. Presiding over a special three-judge coram of the High Court, Sundaresh Menon CJ in Public Prosecutor v Hue An Li 34 surveyed the common law positions in England,35 the United States,36 Canada37 and India38 which have endorsed and/or applied prospective overruling in some form or other. He noted that Australia39 has rejected the doctrine whilst the position in New Zealand40 was equivocal.

The Honourable Chief Justice examined carefully the various arguments for and against prospective overruling. First, he addressed the possible impact of the declaratory theory on the doctrine of prospective overruling. It was thought that the declaratory theory that judges do not create but merely declare the law posed an obstacle for the prospective overruling of law. If that is the case, it might be argued that the rejection of the theory should pave the way for prospective overruling to be accepted. Nevertheless, the Singapore High Court took a measured view, stating that the rejection of the declaratory theory in Singapore per se, as stated in the prior decision of Review Publishing, should not wholly negate the general default position in Singapore that “judicial decisions are unbound by time”.41 That is, judicial decisions should, as a general rule, continue to apply retrospectively and prospectively.

There are other factors to consider. The Chief Justice noted that if such judicial pronouncements were to only apply prospectively, there will not be any incentive for the litigants to persuade the courts to rule in their favour.42 This is compounded by the perceived problem of inequality that, if prospective overruling were to be accepted, similarly-situated litigants after the arbitrary date of the decision pronouncing the legal change would benefit from the change but not those on the other side of the arbitrary line.43 Nevertheless, Menon CJ recognised that the “most compelling” reason for prospective overruling is that of maintaining the rule of law.44 The Chief Justice, citing Hayek (1944)45 and the works of jurisprudential scholars, Raz (1977)46 and Fuller (1964), noted that as people conduct their affairs on the basis of what they understand the law to be, a retrospective change in the law can frustrate legitimate expectations.

To reconcile the opposing arguments for and against prospective overruling, the High Court decided that whilst “judicial pronouncements are, by default, fully retroactive in nature”, the Singapore appellate courts47 have the “discretion, in exceptional circumstances, to restrict the retroactive effect of their pronouncements”.48 Hence, prospective overruling operates within this judicial framework only as an exception to the general default position. Although this was not specifically mentioned by Menon CJ, it is argued that the utilisation of prospective overruling as an exception ameliorates the potential problem of judicial legislation highlighted above and naturally serves as a restriction against the judicial power to only rule prospectively.

Whether the above argument is sound would also depend on the scope of the exception. The relevant question here is the appropriate circumstances in which the courts may exercise the discretion to restrict the retroactive effect of their pronouncements. In this regard, Menon CJ in Public Prosecutor v Hue An Li 49 outlined a framework based on four specific factors to guide judicial discretion:


The extent to which the law or legal principle concerned is entrenched: The more entrenched a law or legal principle is, the greater the need for any overruling of that law or legal principle to be prospective. … …



The extent of the change to the law: The greater the change to the law, the greater the need for prospective overruling…. …



The extent to which the change to the law is foreseeable: The less foreseeable the change to the law, the greater the need for prospective overruling… …



The extent of reliance on the law or legal principle concerned: The greater the reliance on the law or legal principle being overruled, the greater the need for prospective overruling…. …


His Honour was careful to emphasise, however, that “no one factor is preponderant over any other, and no one factor is necessary before prospective overruling can be adopted in a particular case”.50 The above framework extends to both criminal and civil cases.

The present case concerned a charge of causing death by a negligent act, an offence under s 304A(b) of the Penal Code.51 The respondent was sentenced by the District Court to a fine of $10,000 and disqualified from driving for 5 years from the date of her conviction. The Public Prosecutor appealed on the ground that a custodial sentence ought to have been imposed on the respondent. The High Court allowed the appeal and varied the sentence to 4 weeks’ imprisonment. There was an important prior decision which was relevant to determine the appropriate sentence before the High Court namely, Public Prosecutor v Gan Lim Soon.52 Gan Lim Soon decided that there is a distinction between rashness and negligence; for the former, imprisonment would be warranted while for the latter, it would be sufficient in most cases to inflict a fine. Since the decision in Gan Lim Soon, however, section 304A of the Penal Code had been amended in 200853 such that causing death by negligence and causing death by rashness would each have its own sentencing range comprising imprisonment or fine or both.

As a result of the 2008 Penal Code amendments, the High Court in Public Prosecutor v Hue An Li decided that the position laid down in Gan Lim Soon was no longer tenable due to the bifurcation of the old s304A into two limbs in the amended s304A as mentioned above.54 What is important for the purpose of this paper is that the High Court applied prospective overruling to its decision to depart from Gan Lim Soon. Menon CJ reasoned with reference to the factors outlined in the judicial framework for prospective overruling:

  • the shift from a default sentence of a fine to a default sentence of a term of imprisonment is a significant change in the law;

  • there was reliance on Gan Lim Soon in that numerous offenders would have pleaded guilty to or conducted their defences on the basis of advice that the starting point for sentencing in such cases would likely be only a fine; and

  • the change in the law relating to Gan Lim Soon was not foreseeable.55

The above judicial framework for prospective overruling in Public Prosecutor v Hue An Li was applied in the subsequent case of Poh Boon Kiat v Public Prosecutor 56 which was also heard by Menon CJ. The appellant had set up and operated an online vice ring and employed five prostitutes. The appellant pleaded guilty to charges under, inter alia, ss 140 (procuring, receiving and harbouring a prostitute) and 146 (living on immoral earnings) of the Women’s Charter.57 The sentencing precedents had previously treated the imprisonment term for offences under ss 140(1) and 146 of the Women’s Charter as discretionary. However, Menon CJ, upon examining the legislative history of the statutory provisions, held that the sentencing precedents were “incorrect”58 and that the punishment of imprisonment under s 140 and s 146 respectively should be mandatory. Menon CJ invoked prospective overruling in this case on the grounds that the sentencing precedents have “entrenched” the proposition that the starting point in relation to the punishment of first time offenders of ss 140 and 146 without any aggravating factors ought to be a fine.59 Further, His Honour noted that the change in the starting point for the sentences constitutes a “fundamental and unforeseeable change in the law from the appellant’s perspective”.60

The reader would recall that the High Court in Public Prosecutor v Hue An Li referred to the judicial discretion to “restrict the retroactive effect of their pronouncements”61 (instead of the discretion to only apply the pronouncements prospectively i.e., pure prospective overruling). As a preliminary question, one may legitimately inquire if the judicial framework consisting of proposed factors by the Singapore High Court might also apply to a form of limited or qualified prospective overruling (or selective prospective overruling). In this particular form of prospective overruling, the new ruling applies not only to future cases but also to the instant case; however, the old rule is applied to all cases predating the instant decision. There is no indication in Public Prosecutor v Hue An Li that the possibility of applying the framework to a limited form of prospective overruling in the future would be foreclosed.

Consider the scenario where all the factors show that prospective overruling ought to be invoked. We assume here that the reasonable person would not have foreseen the legal change and would have relied on it, the legal change was significant and the existing law was sufficiently entrenched. However, if it is found that the litigant in question had not in fact relied on the existing law due to his special knowledge obtained from particular sources of an impending legal change, and therefore he could foresee the legal change, could selective overruling be applied in such an instance?62 It might be argued that it would not be contrary to the particular litigant’s legitimate expectations for the change of the law to apply to him as well as prospectively.

Comparison may also be made between the factors in Public Prosecutor v Hue An Li and those found in other common law court decisions. The US Supreme Court’s decision in Chevron Oil Company v Gaines Ted Huson 63 laid down three factors to be considered for determining whether prospective overruling was justified, namely: (a) the decision to be applied non-retroactively must establish a new principle of law by overruling a past decision or deciding an issue for the first time; (b) the history, purpose and effect of the rule in question must be analysed to determine if retroactive operation would further or retard its operation; and (c) the inequity imposed by retroactive application must be weighed. The House of Lords in Re Spectrum Plus Ltd (In Liquidation) 64 permitted some leeway for prospective overruling to apply in circumstances where a decision on a point of law was unavoidable but the decision would have seriously unfair and disruptive consequences for past transactions or events. The majority65 stated that the same could apply to both the state of common law as well as a statute.