Critical Assessment of Great Peace Decision on Mistake in Common Law Contract Doctrine

The statement is an accurate representation of the current law of common mistake. The Court of Appeal’s decision in *Great Peace Shipping Ltd v Tsavliris Salvage (International) Ltd* (2002) explicitly abolished the equitable jurisdiction to rescind a contract for common mistake, leaving only the strict, and rarely successful, common law doctrine. This has resulted in a clear but harsh legal position: a contract is either void from the beginning for a fundamental mistake, or it is fully valid, with no middle ground. This represents a decisive victory for the common law’s preference for certainty over the flexibility that equity once offered.

The Divergence of Common Law and Equity

Historically, the common law took a very restrictive approach to mistake. For a contract to be void for common mistake, the mistake had to be so fundamental that it destroyed the very basis of the agreement. The leading case of *Bell v Lever Brothers Ltd* (1932) established a high threshold. Lord Atkin stated that a mistake must be as to the “existence of some quality which makes the thing without the quality essentially different from the thing as it was believed to be” (p. 218). In practice, this meant that only a mistake regarding the actual existence of the subject matter (res extincta) or a similar fundamental error would suffice. This strictness ensured that contracts were not easily undone, promoting commercial certainty.

However, this rigidity was seen by some judges as capable of producing injustice. In response, a more flexible doctrine developed in equity, championed by Lord Denning. In *Solle v Butcher* (1950), Denning MR created a separate test for equitable mistake. He argued that a contract could be voidable in equity (meaning it could be set aside by the court) if the parties were under a “common misapprehension either as to facts or as to their relative and respective rights,” provided that the misapprehension was “fundamental” and the party seeking to set it aside was not at fault (p. 693). This equitable doctrine was much wider than the common law rule in *Bell*. It allowed a contract to be rescinded on terms, even if the mistake was not serious enough to render the contract void at common law. For instance, in *Solle*, a lease was entered into under the mistaken belief that it was not subject to rent controls; the contract was not void at common law, but the court set it aside in equity. This showed a clear battle between two schools of thought: the common law, prioritising certainty, and equity, prioritising fairness and justice in the individual case.

The case of *Associated Japanese Bank (International) Ltd v Credit du Nord SA* (1989) further illustrates this dual approach. Steyn J held that a guarantee for non-existent machines was void for common mistake at common law. However, he went on to say that if he were wrong, he would have held the contract voidable in equity. This demonstrated how the two doctrines could co-exist, providing a safety net of equitable relief where the strict common law test was not met.

The Great Peace Decision: A Return to Orthodoxy

The coexistence of these two doctrines was brought to an abrupt end by the Court of Appeal in *Great Peace Shipping Ltd v Tsavliris Salvage (International) Ltd* (2002). The case concerned the charter of a ship, the *Great Peace*, to provide urgent assistance to another vessel, the *Cape Providence*, which was in distress. Both parties mistakenly believed the ships were only about 35 miles apart, when they were in fact 410 miles apart. When the charterer discovered the truth, they found a closer vessel and sought to cancel the contract with the owners of the *Great Peace*, arguing the contract was void at common law or voidable in equity for common mistake.

The Court of Appeal rejected this claim. More significantly, it took the opportunity to review the entire law of common mistake. Lord Phillips MR, giving the judgment of the court, concluded that the equitable doctrine developed in *Solle v Butcher* could not be reconciled with the binding House of Lords authority in *Bell v Lever Brothers*. He stated that the House of Lords in *Bell* had clearly defined the limits of common mistake, and there was no room for a separate, more lenient equitable principle to operate alongside it. As Lord Phillips put it, “there is no jurisdiction to grant rescission of a contract on the ground of common mistake where that contract is valid and enforceable on ordinary principles of contract law” (*Great Peace*, para 157).

The court therefore overruled *Solle v Butcher* and clarified the single, common law test for mistake. For a common mistake to render a contract void, the non-existent state of affairs must render performance of the contract “impossible” or essentially and radically different from what the parties agreed (para 76). On the facts of *Great Peace*, the extra distance did not make performance impossible; the ship could still have reached the salvage site, albeit later than hoped. The contract was merely a bad bargain for the charterer, not a void one. This decision effectively closed the door on the equitable doctrine, leaving the law in the strict state described by the question.

The Merits of the Post-Great Peace Position

The merits of the statement in the question are clear: it accurately reflects the law. By abolishing equitable mistake, *Great Peace* has confined the doctrine to the narrow common law test. The central merit of this approach, as argued by the Court of Appeal, is the promotion of certainty. Commercial parties can be confident that their contracts will be upheld unless a mistake is so catastrophic as to render performance impossible. This aligns with the principle of *pacta sunt servanda* (agreements must be kept) and avoids the uncertainty that a broad, discretionary equitable power can create. As one academic notes, the decision “re-asserts the primacy of the common law and the importance of certainty in commercial transactions” (McKendrick, 2021). The law is now binary: a contract is either void or valid.

However, this strictness comes at a cost. The key criticism of the *Great Peace* position is its potential for injustice. The “all or nothing” approach leaves no room for a remedy in cases where a mistake is serious and fundamental but does not quite meet the high threshold of rendering performance “impossible”. Parties can be trapped in a contract that neither would have entered into had they known the true facts, simply because performance is still technically possible. The flexibility of equity, as seen in *Solle v Butcher*, was designed to address precisely these kinds of hard cases by allowing a court to rescind the contract, often on terms that sought to do justice to both parties.

The case of *Leaf v International Galleries* (1950), though primarily about mistake as to quality and lapse of time, highlights the type of situation where equity’s flexibility was valuable. The parties mistakenly believed a painting was by the artist Constable. At common law, this was a mistake as to quality that did not void the contract. While rescission was also denied on the facts due to the time that had passed, the case shows that equity provided a potential avenue for relief that the common law did not. After *Great Peace*, that potential avenue is gone. The law has traded tailored justice for rigid certainty.

In conclusion, the statement is a correct assessment of the law of mistake after *Great Peace*. The decision unified the doctrine of common mistake by firmly rejecting the existence of a separate, more lenient jurisdiction in equity. The battle between the common law’s need for certainty and equity’s desire for fairness was decisively won by the common law. The result is a doctrine that is clear and predictable but also inflexible and potentially harsh. Whether the certainty gained is worth the loss of flexibility remains a point of debate, but for now, parties who enter a contract under a serious but non-fundamental common mistake will find that the courts offer them no escape.

References

* *Associated Japanese Bank (International) Ltd v Credit du Nord SA* [1989] 1 WLR 255.
* *Bell v Lever Brothers Ltd* [1932] AC 161.
* *Great Peace Shipping Ltd v Tsavliris Salvage (International) Ltd* [2002] EWCA Civ 1407, [2003] QB 679.
* *Leaf v International Galleries* [1950] 2 KB 86.
* McKendrick, E. (2021) *Contract Law: Text, Cases, and Materials*. 10th edn. Oxford University Press.
* *Solle v Butcher* [1950] 1 KB 671.