which requires parties not to act in a way which is at odds with their prior behaviour, or that this is mandated by the reliance placed upon such behaviour by others.

(a)  The Common law

The position of the Common law with respect to non-agreement based renunciations (including variations) of rights is complicated by the avail­ ability of different claims in common law and equity each of which have the character of a promise.

(i)  Forbearance at common law

At common law, the doctrine of forbearance can operate to prevent a party enforcing its rights (either absolutely or pro tem) in respect of per­ formance due under the contract.42 A forbearance denotes an indication of willingness on the part of a party not to enforce its rights strictly in terms of the contract, but, in response to some request that it do so, to accept some altered performance (for instance, late delivery of goods or payment of a lesser sum due under the contract) or indeed no perform­ ance. The act of forbearance must be unequivocal, and must be acted upon by the party in whose favour it is conceived.43 If such an indication of willingness is unsupported by consideration, though it cannot consti­ tute a contractual variation, it will operate at common law to prevent a claim by the party which has indicated a willingness to forbear for dam­ ages for non-conforming performance, and to preclude that party from refusing such altered performance (if any) in accordance with the terms of its promised forbearance.44

Where the forbearing party has made some express declaration of its willingness, such declaration can be conceived of as a promise, though it may not strictly be couched in promissory terms. Thus, to state ‘I am willing to accept delivery one week late’ can be read as meaning ‘I promise

42See further Peel, Treitel on Contract, paras. 3–069–075; Beale, Chitty on Contracts, paras. 3–057–060, 22–040–047. The prevention may operate pro tem if, for instance, a speci­ fied period of acceptable late performance has been specified. A creditor may withdraw a temporary forbearance by the giving of reasonable notice to the debtor: Banning v. Wright [1972] 1 WLR 972, 981; Ficom SA v. Sociedad Cadex Ltda [1980] 2 Lloyd’s Rep 118, 131; Bremer Handelsgesellschaft mbH v. Raiffeisen Hauptgenossenschaft EG [1982] 1 Lloyds Rep 599. Alternatively, forbearance may operate absolutely if, for instance, goods of a different standard have been accepted by the buyer as conforming goods.

43See Beale, Chitty on Contracts, para. 22–044, and numerous cases cited there.

44See Beale, Chitty on Contracts, 22–042; Peel, Treitel on Contract, 3–072.

that I shall not exercise any remedies for late delivery for a period of a week.’ The same is equally true of conduct indicating forbearance: if such conduct is made in response to a request to forbear, then there is no theo­ retical difficulty in seeing the conduct as indicative of a promise to forbear if it is unequivocally referable to such an intention.45

The benefit from a creditor’s view of pleading forbearance is that con­ sideration does not need to have been given for the forbearance, unlike the case of a full contractual renunciation.46 Whether a statement is intended to operate as a contractual renunciation (and thus to require consideration to be valid) or as forbearance is said to depend on the party’s intentions,47 though sometimes courts have, ex post facto, interpreted statements not supported by consideration as forbearance in order to give them some limited effect.48

Given the promissory nature which may be accorded to acts of forbear­ ance, they are comparable to equitable estoppel, which is also a promissory based doctrine. Indeed, there seems to be little to distinguish common law forbearance from equitable estoppel: while it is a requirement of equi­ table estoppel (but not forbearance) that it be inequitable for the promisor to go back on its promise, given that this requirement of equitable estop­ pel is deemed to be satisfied if the promisee has relied on the promise, and that it is also a requirement of forbearance that the party granted the forbearance must have relied or at least acted on it, the two requirements seem essentially to state the same thing. That being so, all that would seem to distinguish forbearance from equitable estoppel is that the intention of the party forbearing is crucial to the former, whereas it is the conduct of the promisor which is essential to the latter. This distinction, between intent (assessed objectively) and conduct (also assessed objectively) seems a slender basis upon which to set up two distinct doctrines. This may be one example of where the common law/equity division has created an unnecessary duplication of solutions.

(ii)  Forbearance in equity: promissory estoppel in English law

As discussed in Chapter 4 in relation to contract formation, in addition to common law rules, equity also developed remedies to prevent a party

45Bremer Handelssgesellchaft mbH v. Vanden Avenne-Izegem PVBA [1978] 2 Lloyd’s Rep 109.

46See Beale, Chitty on Contracts, para. 3–084.

47Stead v. Dawber (1839) 10 A & E 57, 64.

48Beale, Chitty on Contracts, para. 3–084.

promissory estoppel and is not strictly a direct and full enforcement of the promise in the same way that a valid contractual promise would be.

In order for promised variations of contract such as those in Hughes and High Trees to operate as instances of promissory estoppel, English law has determined that certain requirements must be met: (i) the parties must be in a pre-existing legal relationship; (ii) a promise, or an equiva­ lent assurance, must have been made by A; (iii) the promise must be clear and unequivocal, though it need not be express (as it was not in Hughes v. Metropolitan Railway). Acceptance by A of B’s defective performance will not constitute such an unequivocal, deemed promise by A to treat such performance as fulfilling B’s contractual duty so long as A reserves its strict contractual rights;52 and (iv) B must have relied on the promise to some extent, so that it would be inequitable to allow A to go back on its promise.

(iii)  Promissory estoppel in American Common law

The development of promissory estoppel in modern American con­ tract law has been no less dramatic than in English law. As noted in Chapter 4, the American courts proved themselves willing to assume reliance or overlook the need for it, effectively moving the law towards a position where promises which might be assumed to give rise to reliance were enforced. This development suggests the true nature of liability under promissory estoppel to be promise and not reliance. American courts have, for instance, either ignored or assumed the reliance requirement in cases of marriage settlements (where there has been no enquiry whether the promisee only married in reliance on the promise) and in the enforcement of promises to charitable organisations (where again there has been no enquiry of whether the charity relied on the promise). In fact, in these two specific areas, the Restatement (Second) of Contracts has legislated to the effect that the promise will be bind­ ing without proof of reliance (whether by action or forbearance).53 From an outside perspective, it seems somewhat curious to select these two quite unrelated types of promise as alone being worthy of this presump­ tion: why should other promisees not be equally worthy of the benefit of the provision?

52Failure to do so may constitute such deemed unequivocal promise to accept defective performance: see, for instance, Bremer Handelsgesellchaft mbH v. Vanden Avenne-Izegem PVBA [1978] 2 Lloyd’s Rep 109.

53Restatement (Second) of Contracts, §90(2).

Promissory estoppel has also been held to apply in American juris­ dictions to cases where a promise has been made to do some service gratuitously for the promisee, some cases involving promises made to the other contracting party after the contract was formed (and hence amounting to variations of existing duties), others promises to a third party.54 As in English law, some commentators have argued that such cases demonstrate that promissory estoppel is in fact a species of reli­ ance-based liability. However, it is striking that the promisee is often not required to show, or even allege in some cases, any detrimental reli­ ance on the promise. It seems therefore more satisfactory to see them as indicative of a desire of American Common law to move towards a wider recognition of promissory liability in general, even in the absence of mutual consideration.55

It is significant that the provision in the Restatement (Second) of Contracts on ‘Promises reasonably inducing action or forbearance’ (§90) does not see promissory estoppel as a mere defence to a claim (as in English law) but rather provides that where a promise which the promisor should reasonably expect to induce action or forbearance on the part of the promisee or a third party, has just such an effect, it is binding if injus­ tice can be avoided only by enforcement of the promise. Such a prom­ ise is thus fully binding on the promisor and gives the promisee title to sue as well as all the usual contractual remedies. This is clearly an even larger inroad to the rule of consideration than is the case with promissory ­estoppel in English law.

54Cases where promissory estoppel has been applied have included the following facts: a seller of property agreed to file papers to insure it (Dalrymple v. Ed Shults Chevrolet, Inc. 380 N.Y.S.2d 189, 190 (App Div 1976)); a railway company promised to help a cus­ tomer by filing papers with the Government (Carr v. Maine Central R.R. Co. 102 A. 532 (N.H. 1917)); the holder of a security over property promised to insure it at the prom­ isee’s expense (East Providence Credit Union v. Geremia 239 A.2d 725 (R.I. 1968)); the senior creditor in a financing arrangement offered to give notice of default to the junior creditor (Miles Homes Div. of Insilco Corp. v. First State Bank 782 W.W.2d 798 (Mo. Ct. App. 1990)); a main contractor agreed to write cheques payable to the subcontractor’s supplier, rather than to the supplier itself (United Electric Corp. v. All Serv. Elec., Inc. 256 N.W.2d 92, 95–96 (Min. 1977)). Further cases are mentioned by Gordley, ‘Louisiana and the Common Law’.

55Gordley has argued of such cases that the ‘doctrine of promissory estoppel does not explain these cases. The best explanation is that when the promisor enters into the sort of transaction which is known to civil law as mandate, his promise is enforceable without regard either to consideration or reliance’ (Gordley, ibid., p. 203).