Accordingly, since the Plaintiff never raised any queries regarding the monthly statements of account within the specified 60 day period, the Plaintiff should be estopped from now seeking to query the transactions set out in the monthly statements of account. In Boustead Trading (1985) Sdn Bhd v Arab –Malaysian Merchant Bank Bhd [1995] 3 MLJ 331, the Federal Court said this at pages 344 to 346: “The time has come for this court to recognize that the doctrine of estoppel is a flexible principle by which justice is done according to the circumstances of the case. It is a doctrine of wide utility and has been resorted to in varying fact patterns to achieve justice. Indeed, the circumstances in which the doctrine may operate are endless. Edgar Joseph Jr J (as he then was) in an illuminating judgment in Alfred Templeton & Ors v Low Yat Holdings Sdn Bhd & Anor [1989] 2 MLJ 202 at p 244 applied the doctrine in a broad and liberal fashion to prevent a defendant from relying upon the provisions of the Limitation Act 1952. The doctrine may be applied to enlarge or to reduce the rights or obligations of a party under a contract: Sarat Chunder Dey v Gopal Chunder Laha LR 19 IA 203; Amalgamated Investment and Property Co Ltd (In liquidation) v Texas Commerce International Bank Ltd [1982] 1 QB 84; [1981] 3 All ER 577; [1981] 3 WLR 565. It has operated to prevent a litigant from denying the validity of an 22 otherwise invalid trust (see, Commissioner for Religious Affairs, Trengganu & Ors v Tengku Mariam bte Tengku Sri Wa Raja & Anor [1970] 1 MLJ 222) or the validity of an option in a lease declared by statute to be invalid for want of registration (see, Taylor Fashions Ltd v Liverpool Victoria Friendly Society [1981] 1 All ER 897; [1981] 2 WLR 576). It has been applied to prevent a litigant from asserting that there was no valid and binding contract between him and his opponent (see, Waltons Stores (Interstate) Ltd v Maher (1988) 164 CLR 387) and to create binding obligations where none previously existed (see, 1995 3 MLJ 331 at 345 Spiro v Lintern [1973] 3 All ER 319; [1973] 1 WLR 1002). It may operate to bind parties as to the meaning or legal effect of a document or a clause in a contract which they have settled upon (see the Amalgamated case) or which one party to the contract has represented or encouraged the other to believe as the true legal effect or meaning: American Surety Co of New York v Calgary Milling Co Ltd (1919) 48 DLR 295; De Tchihatchef v Salerni Coupling Ltd [1932] 1 Ch 330; Taylor Fashions. We would add that it is wrong to apply the maxim 'estoppel may be used as a shield but not a sword' as limiting the availability of the doctrine to defendants alone. Plaintiffs too may have recourse to it. The true nature of the doctrine in this context is that stated by Lord Russell of Killowen in Dawsons Bank v Nippon Menkwa Kabushiki Kaisha LR 62 IA 100 at p 108: Estoppel is not a cause of action. It may (if established) assist a plaintiff in enforcing a cause of action by preventing a defendant from denying the existence of some fact essential to establish the cause of action, or 23 (to put it in another way) by preventing a defendant from asserting the existence of some fact the existence of which would destroy the cause of action. It is also wrong to think that the doctrine is confined to cases where a representation of fact has been made or where a party has been encouraged by another to believe in the existence or in the non-existence of a fact. The decisions of the Privy Council in Sarat Chunder Dey and the Calgary Milling Co (among others) to which we have referred earlier concerned cases involving representations not of fact but of law. The width of the doctrine has been summed up by Lord Denning in the Amalgamated Investment case ( [1982] 1 QB 84 at p 122; [1981] 3 All ER 577 at p 584; [1981] 3 WLR 565 at p 575) as follows: The doctrine of estoppel is one of the most flexible and useful in the armoury of the law. But it has become overloaded with cases. That is why I have not gone through them all in this judgment. It has evolved during the last 150 years in a sequence of separate developments: proprietary estoppel, estoppel by representation of fact, estoppel by acquiescence, and promissory estoppel. At the same time it has been sought to be limited by a series of maxims: estoppel is only a rule of evidence, estoppel cannot give rise to a cause of action, estoppel cannot do away with the need for consideration, and so forth. All these can now be seen to merge into one general principle shorn of limitations. When the parties to a transaction proceed on the basis of 24 an underlying assumption – either of fact or of law – whether due to misrepresentation or mistake makes no difference – on which they have conducted the dealings between them – neither of them will be allowed to go back on that assumption when it would be unfair or unjust to allow him to do so. If one of them does seek to go back on it, the courts will give the other such remedy as the equity of the case demands. (Emphasis added.) In Lim Teng Huan v Ang Swee Chuan [1992] 1 WLR 113, an appeal from Brunei Darussalam, the Privy Council said that the decision in the Taylor Fashions case: … showed that, in order to found a proprietary estoppel, it is not essential that the representor should have been guilty of unconscionable conduct in permitting the representee to assume that he could act as he did: it is 1995 3 MLJ 331 at 346 enough if, in all the circumstances, it is unconscionable for the representor to go back on the assumption which he permitted the representee to make (per Lord Browne-Wilkinson at p 117). The essential nature of the doctrine does not appear to be any different in American equity jurisprudence. This is reflected by the following passage in the opinion of the Supreme Court of the United States in Dickerson v Colgrove (1880) 100 US 578 at p 580 (25 L Ed 618) delivered by Swayne J: 25 The estoppel here relied upon is known as an equitable estoppel, or estoppel in pais. The law upon the subject is well settled. The vital principle is, that he who, by his language or conduct, leads another to do what he would not otherwise have done, shall not subject such person to loss or injury by disappointing the expectations upon which he acted. Such a change of position is sternly forbidden. It involves fraud and falsehood, and the law abhors both. This remedy is always so applied as to promote the ends of justice. Thus far we have dealt with the operation of the doctrine in the context of there having been offered some active encouragement by the party sought to be estopped. But we do not apprehend the law to be different when the encouragement comes in the form of silence. The true principle in such cases is to be found in the following passage in the judgment of Thesiger LJ in De Bussche v Alt (1878) 8 Ch D 286 at p 314: If a person having a right, and seeing another person about to commit, or in the course of committing an act infringing upon that right, stands by in such a manner as really to induce the person committing the act, and who might otherwise have abstained from it, to believe that he assents to its being committed, he cannot afterwards be heard to complain of the act.”