Lloyd's Maritime and Commercial Law Quarterly
THE OFFENSIVE LIMITS OF PROMISSORY ESTOPPEL
Roger Halson*
The subject-matter of this article is the contractual doctrine of promissory estoppel. In particular it explores the limits of the doctrine when used as a “weapon” of attack. Five different limits are identified, each of which finds support in domestic and overseas case law. The first major conclusion is that there is a need for greater clarity in expressing the proper limits of the doctrine. The policy considerations which inform promissory and other estoppel doctrines are then examined. It is noted that promissory estoppel has been developed to address problems associated with the modification of pre-existing, rather than the formation of new, contracts. The article concludes that this expertise and experience in addressing issues involving the alteration of contracts will be lost or disguised if promissory estoppel is regarded as part of a wider unified doctrine of estoppel capable of creating a cause of action of itself.
I. INTRODUCTION1
Lawyers love metaphors. Never more so than when discussing the limits of estoppel. In the introduction to one of the classic works on estoppel the editor writes:2 “To use the language of naval warfare, estoppel must always be either a mine layer or a mine sweeper: it can never be a capital unit.” More famous perhaps is the “vivid” phrase used by counsel,3 and approved by Birkett, L.J.,4 in Combe v. Combe which described the doctrine of promissory estoppel as one to be used “as a shield and not as a sword”. Yet such language can be confusing; it often conceals subtle shades of meaning. This article has two aims. First, it seeks to describe the offensive limits of the doctrine as it has been developed in this country and overseas. This is an account, shorn of metaphor and simile, of the offensive use of promissory estoppel,5 which should be intelligible to someone born too late to remember the naval conflict of the First World War and who is unversed in the
* Senior Lecturer in Laws. University College London. I would like to thank Lord Steyn, Professor Ewan McKendrick, Professor J. C. Smith and Nicholas Banforth for their comments on an earlier draft of this article. However, for the errors and infelicities that remain, I stand alone.
1. The following abbreviations are used in these footnotes: Cheshire, Fifoot & Furmston: Cheshire, Fifoot & Furmston, The Law of Contract, 12th edn (1996). Spencer Bower & Turner: Spencer Bower & Turner, Estoppel by Representation, 3rd edn (1977). Treitel: (Sir) G. H. Treitel, The Law of Contract, 9th edn (1995).
2. Spencer Bower & Turner, 7.
3. [1951] 2 K.B. 215, 218.
4. Ibid., 224. Cf. Re Tudale Exploration and Bruce (1978) 20 O.R. 2d 593, 597, per Grange, J.
5. When estoppel is referred to in the remainder of this article, promissory estoppel is meant.
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