the scope of the retrospective operation of the law declared by the Supreme Court superseding its earlier decisions is left to its discretion to be moulded in accordance with-the justice of the cause or matter before it. [143] In Sarwan Kumar v. Madan Lal Aggarwal AIR 2003 Supreme Court 147 the Supreme Court defined prospective overruling as: the law declared by the Court applies to the cases arising in future only and its applicability to the cases which have attained finality is saved because the repeal would otherwise work hardship to those who had trusted to its existence. [144] It is said that the prospective declaration of law is a device innovated by the apex court to avoid reopening of the settled issues and to prevent multiplicity of proceedings. It is also a device adopted to avoid uncertainty and avoidable litigation. By the very object of the prospective declaration of law, it is deemed that all actions taken contrary to the declaration of law prior to its date of declaration are validated. This is done in the larger public interest. Therefore, the subordinate forums which are legally bound to apply the declaration of law made by this Court are also duty bound to apply such cases which would arise in future only. [145] It was held in Golak Nath that this doctrine can only be invoked in matters arising under the Constitution and can be applied only by the Supreme Court in its discretion in accordance with the justice of the cause or matter before it. But it has now been held that application of the doctrine of prospective overruling has been extended to the interpretation of the ordinary statutes as well. [146] The basic objective of prospective overruling is to overrule a precedent without having a retrospective effect. Retrospective invalidation of governmental acts may have far reaching consequences especially when many parties have relied on the act and there are financial considerations and consequences involved. [147] In Re Spectrum Plus Ltd [2005] UKHL 41 the House of Lords through the judgment of Lord Nicholls of Birkenhead discussed the application of prospective overruling and highlighted the basic features of the judicial system. The role of the courts is to decide the legal consequences of past happenings. The courts make findings on disputed questions of fact, identify and apply the relevant law to the findings of facts and award the appropriate remedies. The second feature is the effect of a court decision on a point of law. In order to ensure a degree of consistency and certainty about the present state of the law the courts in the UK adopted the practice of treating decisions on a point of law as being the precedents for the future i.e. the principle of stare decisis, if in the event similar issue of law arises in another case a court will treat a previous decision as binding or persuasive. His Lordship explained that the third feature is that "From time to time court decisions on points of law represent a change in what until then the law in question was generally thought to be. This happens when a court departs from, or an appellate court overrules, a previous decision on the same point of law. The point of law may involve the interpretation of a statute or it may relate to a principle of 'judge-made' law, that is, the common law. A change of this nature does not always involve departing from or overruling a previous court decision. There are times when a court may give a statute, until then free from judicial interpretation, a different meaning from that commonly held." [148] The fourth feature is a consequence of the second and third features: A court ruling which changes the law from what it was previously thought to be operates retrospectively as well as prospectively. The ruling will have a retrospective effect so far as the parties to the particular dispute are concerned, as occurred with the manufacturer of the ginger beer in Donoghue v Stevenson [1932] AC 562. When Mr Stevenson manufactured and bottled and sold his ginger beer the law on manufacturers' liability as generally understood may have been as stated by the majority of the Second Division of the Court of Session and the minority of their Lordships in that case. But in the claim Ms Donoghue brought against Mr Stevenson his legal obligations fell to be decided in accordance with Lord Atkin's famous statements. Further, because of the doctrine of precedent the same would be true of everyone else whose case thereafter came before a court. Their rights and obligations would be decided according to the law as enunciated by the majority of the House of Lords in that case even though the relevant events occurred before that decision was given. [149] The House of Lords further explained that prospective overruling takes several forms: In its simplest form prospective overruling involves a court giving a ruling of the character sought by the bank in the present case. Overruling of this simple or 'pure' type has the effect that the court ruling has an exclusively prospective effect. The ruling applies only to transactions or happenings occurring after the date of the court decision. All transactions entered into, or events occurring, before that date continue to be governed by the law as it was conceived to be before the court gave its ruling. Other forms of prospective overruling are more limited and 'selective' in their departure from the normal effect of court decisions. The ruling in its operation may be prospective and, additionally, retrospective in its effect as between the parties to the case in which the ruling is given. Or the ruling may be prospective and, additionally, retrospective as between the parties in the case in which the ruling was given and also as between the parties in any other cases already pending before the courts. There are other variations on the same theme. [150] The House of Lords in Spectrum did not apply the doctrine of prospective overruling but said that prospective overruling may be necessary in certain circumstances to administer justice fairly: [40] Instances where this power has been used in courts elsewhere suggest there could be circumstances in this country where prospective overruling would be necessary to serve the underlying objective of the courts of this country: to administer justice fairly and in accordance with the law. There could be cases where a decision on an issue of law, whether common law or statute law, was unavoidable but the decision would have such gravely unfair and disruptive consequences for past transactions or happenings that this House would be compelled to depart from the normal principles relating to the retrospective and prospective effect of court decisions. [41] If, altogether exceptionally, the House as the country's supreme court were to follow this course I would not regard it as trespassing outside the functions properly to be discharged by the judiciary under this country's constitution. Rigidity in the operation of a legal system is a sign of weakness, not strength. It deprives a legal system of necessary elasticity. Far from achieving a constitutionally exemplary result, it can produce a legal system unable to function effectively in changing times. 'Never say never' is a wise judicial precept, in the interest of all citizens of the country [151] Lord Nicholls said that judges had been described as "developing" the law for some time when making novel decisions, and that judges are not free to repeal laws or distance themselves from bad laws; their only power is to impose a new interpretation. His Lordship held that in exceptional cases, it would be open to the court to hold that a new interpretation of the law should be applied only prospectively: But, even in respect of statute law, they do not lead to the conclusion that prospective overruling can never be justified as a proper exercise of judicial power. In this country the established practice of judicial precedent derives from the common law. Constitutionally the judges have power to modify this practice. [152] What can be discerned from the House of Lords 'decision in Re: Spectrum is that there can be exceptional circumstances where it is necessary in the interest of justice that the decision of the court must be prospective. [153] The Canadian Supreme Court in Canada (Attorney General) v Hillsop [2007] SCR 429 addressed the subject of retrospectivity of laws and its judgment said: People generally conduct their affairs based on their understanding of what the law requires. Governments in this country are no different. Every law they pass or administrative action they take must be performed with an eye to what the Constitution requires. Just as ignorance of the law is no excuse for an individual who breaks the law, ignorance of the Constitution is no excuse for governments. But where a judicial ruling changes the existing law or creates new law, it may, under certain conditions, be inappropriate to hold the government retroactively liable. An approach to constitutional interpretation that makes it possible to identify, in appropriate cases, a point in time when the law changed, makes it easier to ensure that persons and legislatures who relied on the former legal rule while it prevailed will be protected. In this way, a balance is struck between the legitimate reliance interests of actors who make decisions based on a reasonable assessment of the state of the law at the relevant time on one hand and the need to allow constitutional jurisprudence to evolve over time on the other. [154] Consistent with the approach in the United Kingdom and Canada this Court in Tenaga Nasional Berhad v Kamarstone Sdn Bhd (supra) had stated that where it concerns the construction or interpretation of statue, a statue should not be interpreted retrospectively to impair an existing right or obligation: [5] ... Still, we could take this opportunity to uphold that it is indeed a rule of construction that a statute should not be interpreted retrospectively to impair an existing right or obligation, unless such a result is unavoidable by reason of the language used in the statute (Yew Bon Tew & Anor v Kenderaan Bas Mara [1983] 1 MLJ 1 per Lord Brightman, delivering the advice of the Board). [6] In National Land Finance Co-Operative Society Ltd v Director General of Inland Revenue [1994] 1 MLJ 99,p106 Gunn Chit Tuan CJ (Malaya) said: On the retrospective operation of Acts, the presumption is that an enactment is not intended to have a retrospective operation unless a contrary intention appears. In this case, that presumption has been rebutted because s 1(5) of the Amendment Act states in clear terms that the amendment was intended to be retrospective. But a retrospective operation should not be given to a statute to impair an existing right and it has been stated by the UK Court of Appeal in EWP Ltd v Moore [1992] 1 All ER 880 at p 891: ... that those who have arranged their affairs, as the saying is, in reliance on a decision of these courts which has stood for many years should not find that their plans have been retrospectively upset ... Moreover, one should avoid a construction that inflicts a detriment and as Lord Brightman has said in Yew Bon Tew v Kenderaan Bas Mara [1983] 1 MLJ 1 at p 2: A statute is retrospective if it takes away or impairs a vested right acquired under existing laws, or creates a new obligation or imposes a new duty, or attaches a new disability, in regard to events already past. [7] If it takes away a substantive right, the amendment will not have retrospective effect save by clear and express words. If it is procedural, retrospectivity applies unless otherwise stated in the statute concerned (MGG Pillai v Tan Sri Dato' Vincent Tan Chee Yioun [2002] 2 MLJ 673 per Steve Shim CJ (Sabah & Sarawak). If the Legislature intends an amendment to have retrospective application, it must expressly and clearly say so (see Puncakdana Sdn Bhd v Tribunal for Housebuyers Claims and another application [2003] 4 MLJ 9 per Md Raus J, as he then was). [155] Prospective overruling and retrospectivity have been discussed and applied in many cases decided by the Federal Court. In Letchumanan Chettiar Alagappan @ L Alagappan (as executor to SL Alameloo Achi alias Sona Lena Alamelo Acho, deceased) & Anor v Secure Plantation Sdn Bhd [2017] 4 MLJ 697 retrospective application of a decision of the Federal Court case was discussed. In Letchumanan (supra) the main issue for the court's determination is the standard of proof in a civil claim when fraud is alleged. The Federal Court in Letchumanan (supra) considered whether the principles enunciated in Sinnaiyah & Sons Sdn Bhd v Damai Setia Sdn Bhd [2015] 5 MLJ 1 where it was held that in a civil claim even when fraud is alleged the civil standard of proof, that is, on the balance of probabilities, should apply in the absence of a statutory provision. With respect to whether prospective overruling applies in Letchumanan, Jeffery Tan, FCJ said: [88] In Malaysia, the doctrine of prospective overruling had been applied in criminal cases and in an application that pertained to a court circular on auction sale (Tan Beng Sooi v Penolong Kanan Pendaftar (United Merchant Finance Bhd, intervener) [1995] 2 MLJ 421). In Public Prosecutor v Dato' Yap Peng [1987] 2 MLJ 311, it was held by the former Supreme Court (majority) that s 418A of the Criminal Procedure Code was unconstitutional and void as being an infringement of the provisions of art 121(1) of the Federal Constitution and that the doctrine of prospective overruling would be applied so as not to give retrospective effect to the declaration made with the result that all proceedings of convictions and acquittals which had taken place under the section prior to the date of that judgment would remain undisturbed and not be affected. In Mamat bin Daud & Ors v Government of Malaysia [1988] 1 MLJ 119, it was declared by the former Supreme Court (majority) that s 298A of the Penal Code was invalid and therefore null and void and of no effect but that the declaration would not apply to the Federal Territories of Kuala Lumpur and Labuan and would take effect from the date of the order, that is 13 October 1987. In Repco Holdings Bhd v Public Prosecutor [1997] 3 MLJ 681, the Court of Appeal, per Gopal Sri Ram JCA (as he then) was, delivering the judgment of the court, declared both s 129(2) of the Securities Industry Act 1983 and s 39(2) of the Securities Commission Malaysia Act 1993 to be unconstitutional, null and void, but the declaration was prospective only, to include that case and cases registered from the date of the declaration. [89] Prospective overruling had been applied in Malaysia. But was it applied in Sinnaiyah, such that it had no retrospective effect, even to the instant appeal from a decision decided by the trial court before the change in the law? 'It is a fundamental principle of adjudicative jurisprudence that all judgments of a court are retrospective in effect' (Abdillah bin Labo Khan v Public Prosecutor [2002] 3 MLJ 298 per Gopal Sri Ram JCA, as he then was, delivering the judgment of the court). 'The law as so stated applies not only to that case but also to all cases subsequently coming before the courts for decision, even though the events in question in such cases occurred before the ... decision was overruled' (Kleinwort Benson Ltd). 'Because of the doctrine of precedent, the same would be true of everyone else whose obligations would be decided according to the law as enunciated ... even though the relevant events occurred before that decision was given' (Lord Nicholl's fourth 'feature' in the judicial system, see also Public Prosecutor v Mohd Radzi bin Abu Bakar [2005] 6 MLJ 393, where it was held by the court per Gopal Sri Ram JCA, (as he then was), delivering the judgment of the court, that the Court of Appeal was bound to follow Muhammed bin Hassan, notwithstanding that the conviction was handed down before the change in the law). The law as so stated in a superior judgment would apply to cases which have not yet gone to trial or are still in progress and to appeals that have been brought timeously but have not yet been concluded (Cadder v Her Majesty's Advocate per Lord Hope) and to matters or cases not yet finally determined, but the retrospective effect of a judicial decision is excluded from cases already finally determined (Cadder v Her Majesty's Advocate per Lord Rodger). That is the common law position. There was no departure in Sinnaiyah from the common law position when the court said 'we should make it clear that this judgment only applies to this appeal and to future cases and should not be utilised to set aside or review past decisions involving fraud in civil claims. The court merely underscored the retrospective and prospective effect of its decision, to apply to that appeal and to future cases, to cases as yet not filed and trials or appeals which have yet to be finally determined, but not to past cases which have reached a terminal end. The ruling in Sinnaiyah was not in the prospective only form. Sinnaiyah applies to all cases that have not been finally determined, including all pending appeals, except that in the instant appeal, it does not matter. [156] It is necessary to highlight that the facts and the laws applicable in both Letchumanan and Sinnaiyah are distinguishable from the appeals before us. The issue before this Court in both Letchumanan and Sinnayah involved fraud and forgery in land transactions in civil claims and the applicable standard of proof. [157] This court in Busing ak Jali & Ors v Kerajaan Negeri Sarawak & Anor and other appeals [2022] 2 MLJ 273 had also addressed the issue of retrospectivity and prospective overruling. In Busing the questions of law for the court's determination were related to the decision of the Federal Court in the case of Director of Forest, Sarawak & Anor v TR Sandah ak Tabau & Ors (suing on behalf of themselves and 22 other proprietors, occupiers, holders and claimants of native customary rights land situated at Rumah Sandah and Rumah Lanjang, Ulu Machan Kanowit) and other appeals [2017] 2 MLJ 281 and the decision of the Federal Court in the case of TH Pelita Sadong Sdn Bhd & Anor v TR Nyutan ak Jami & Ors and other appeals [2018] 1 MLJ 77 and the decision of the Court of Appeal in Superintendent of Lands & Surveys, Bintulu v Nor Anak Nyawai & Ors and another appeal [2006] 1 MLJ 256 vis a vis the 2018 amendments to the Sarawak Land Code. Tan Sri Abang Iskandar Abang Hashim, CJSS (as His Lordship then was) delivering the judgment of the Federal Court said: [141] It is trite legal principle that a legislative change in a statute is not intended to have a retrospective effect 'unless a contrary intention is evinced in express and unmistakable terms or in a language which is such that it plainly requires such a construction ...' (Ireka Engineering & Construction Sdn Bhd v PWC Corp Sdn Bhd and other appeals [2020] 1 MLJ 311). [142] In fact, there is, at common law, a general rule 'that a statute changing the law ought not, unless the intention appears with reasonable certainty, to be understood as applying to facts or events that have already occurred in such a way as to confer or impose or otherwise affect rights or liabilities which the law had defined by reference to the past events (Sir Owen Dixon CJ in Maxwell v Murphy[2022] 2 MLJ 273 at 318(1957) 96 CLR 261). [158] In Busing, the Federal Court had to determine whether the 2018 amendment to the Sarawak Land Code, in respect of the issues on Pemakai Menoa and Pulau Galau; and deferred indefeasibility of provisional lease; and the effect of the amendment to the appeals before it. The Federal Court concluded that the current regime of the statutory law must be complied with not only to cases which are yet to be filed with the courts, but also to all pending cases and all those cases still under appeals within our court system. [159] Busing and the appeals before us are distinguishable on the facts and the law in that in Busing there was an amendment to the statute whereas in the appeals before us the declaration by this court that the regulation is ultra vires the Act. [160] In Ang Ming Lee this Court declared that Regulation 11 (3) HDR ultra vires the HDA, and thus, the extension granted by the Controller was invalid. Ang Ming Lee, however, is silent as to whether the effect of declaring Regulation 11 (3) HDR ultra vires would apply retrospectively or prospectively. This means that any extension granted by the Controller would be invalid prior to Ang Ming Lee and house buyers would be entitled to LAD to be calculated up to Ang Ming Lee notwithstanding the fact that they may have been paid LAD and vacant possession have been delivered. This cannot be so, as it will result in substantive injustice as it will impair the rights of the parties involved. At the time the extension was granted the law, that is Regulation 11(3) HDR was valid and reliance was placed based not only on the statutory regime at that time allowing such extension to be granted and extending the prescribed 36 months completion period but also the terms of the executed SPAs were based on the approved extension as required by the law. [161] Learned Counsels for Obata and Vignesh, Dato KL Wong and Dato Low Joo Hean submitted at length that the Courts' role is only to interpret the law and as such may not be permitted to impose prospective effect of any ruling akin to legislative's act of making law and in any event, they are not permitted to violate the equal protection principle that transcends adjudicative jurisprudence in all the common law courts. The prospective overruling referred to in the various authorities are pronouncements which are consistent with retrospective effect of the decisions. Therefore, since these appeals had been filed after Ang Ming Lee was decided, there is no infringement of the doctrine even if the principle is applied herein. [162] Learned counsels further argued that it is now too late to retrospectively impose prospective effect to Ang Ming Lee as the rights under Article 8 of the Federal Constitution of the Appellant and many plaintiffs whose cases are pending in various courts will be violated as just like Ang Ming Lee who suffered the illegal act of the controller by virtue of the illegal extension of time to the developer prior to the decision in Ang Ming Lee, the Appellant and most of the plaintiffs whose cases are pending in various courts suffered also illegal extension of time granted by the controller prior to decision of Ang Ming Lee. [163] We are not persuaded with the arguments advanced by learned counsels for Obata and Vignesh. The exception as enunciated in Re: Spectrum suggested the application prospective overruling is an ideal resolution such that any changes in the law will not affect any causes of action in respect of extension of time and LAD arising prior to Ang Ming Lee. The Court may, after having considered the justice of the case and in exceptional circumstances must be prepared to hold that a new interpretation of the law should be applied only prospectively. The declaration of ultra vires and invalidity in Ang Ming Lee cannot be interpreted as giving an opportunity to all that have benefited prior to Ang Ming Lee to enjoy further financial gains. [164] The statutory regime at the time when extension was applied and granted was valid. As we have stated above great reliance was placed by both the developers and controller that the authority exists. The Minister was empowered to delegate the power to grant extension to the controller. Furthermore, the parties, that is, the developers and the purchasers had relied and accepted the terms of the SPAs where the extended completion period approved by the Controller had been expressly provided. Parties are bound by the terms of the contract and cannot rewrite the terms which they have accepted and from which they have benefitted. [165] As submitted by learned Senior Federal Counsel, Liew Horng Bin, amicus curiae, a retrospective invalidation of a legislation undermines legal certainty and predictability. Unless there is exceptional public interest requiring retrospective application, an order invalidating a legislation should only take effect prospectively. The invalidation of a legislation or any provision of the legislation would have serious ramifications and implications on those who would have relied on its validity in the past. There will not only be potential administrative chaos but commercial chaos affecting the housing industry which may affect house buyers as well. In Boddington v British Transport (supra) Lord Browne-Wilkinson opined that: he was far from satisfied that an ultra vires act is incapable of having any legal consequence during the period between the doing of that act and the recognition of its invalidity by the court. During that period people will have regulated their lives on the basis that the act is valid. The subsequent recognition of its invalidity cannot rewrite history as to all the other matters done in the meantime in reliance on its validity. [166] Therefore, a careful consideration of the reliance interest is not only necessary but critical. Undoubtedly, laws must be given their full force and effect until they are declared invalid. An administrative decision made pursuant to a valid legislation before it is declared as ultra vires does not mean that the decision was void ab initio. It remains validly and legally intact. [167] We have given our utmost consideration on the facts and the law and we are of the view that if Ang Ming Lee is to have retrospective effect there would be serious ramifications and repercussions to the housing developers that had placed reliance on the existing law and diligently complied with the laws which were at that time valid. [168] Therefore, based on the reasons we have stated above and the exceptional circumstances involved, the decision of Ang Ming Lee is prospective. To say otherwise that Ang Ming Lee applies retrospectively will result in great injustice and devastating consequences to the housing industry that had diligently complied with the laws before Ang Ming Lee. Thus, the principles enunciated in Ang Ming Lee will not apply to extensions granted by the Controller before Ang Ming Lee. [169] In respect of prospective overruling we answered as follows: Question 1 Does the doctrine of prospective overruling and the exceptions set out in Re Spectrum Plus Ltd (in liquidation) [2005] 2 AC 680 ("Spectrum Plus") apply to Malaysian cases where a court's decision and/or judicial pronouncement would bring disruptive consequences to an industry as a whole? Answer: Affirmative Question 2 Does the reliance test (the greater the reliance on the law or legal principle being overruled, the greater the need for prospective overruling) apply to Malaysian cases where great reliance was placed on a statutory regime? Answer: Affirmative Unjust Enrichment [170] We now turn to the arguments in respect of unjust enrichment claims. The HDA and the regulations made thereunder are social legislations with the paramount intention to protect the interest of purchasers. In order to achieve and fulfil this housing developers must be regulated to ensure that house buyers are at all times protected from unscrupulous developers who had promised to deliver their dream houses purchased within the time as stipulated in the SPA. Unfortunately, before the requirement of approved extension there were incidents where housing developers had extended the period of completion beyond the time expressly stipulated without any notice to the purchasers and some developers even extended the time of completion and delivery of vacant possession ad infinitum resulting in abandoned projects. [171] In its wisdom the Legislature enacted the HDA and the Minister in charge of Housing and Local Government made the Regulations pursuant to the HDA prescribing the standard form of agreement and the requirement for approval before any changes could be made to the prescribed agreement. Until Ang Ming Lee, approval was mandatory before any amendments or variations could be implemented. Some applications were allowed and some were not. This was to ensure that any extended time of completion will be regulated and monitored to ensure that housing developers will deliver vacant possession. In the appeals before us the developers had sought for approval prior to executing the SPAs. [172] The Federal Court in Dream Property Sdn Bhd v. Atlas Housing Sdn Bhd [2015] 2 MLJ 441 recognised the principle of unjust enrichment under Malaysian law. Through the judgment of Azahar Mohamed FCJ (as he then was) his Lordship eloquently explained the determinative principles to be applied: [117] The above passages from the judgments of the House of Lords are instructive and are significant contribution to the development of law of unjust enrichment. The principle underlying the cases of Banque Financiere de la Cite v Parc (Battersea) Ltd and Sempra Metals Ltd (formerly Metallgesellschaft Ltd) v IRC is that, in the context of the present case, a cause of action in unjust enrichment can give rise to a right to restitution where it can be established that: