Actionable Torts in UK Law

In my opinion, and subject to one qualification, acts against a third party count as unlawful means only if they are actionable by that third party. The qualification is that they will also be unlawful means if the only reason why they are not actionable is because the third party has suffered no loss. But the threat must be to do something which would have been actionable if the third party had suffered loss.

Your Lordships were not referred to any authority in which the tort of causing loss by unlawful means has been extended beyond the description given by Lord Watson in Allen v Flood [1898] AC 1, 96 and Lord Lindley in Quinn v Leathem [1901] AC 495, 535. In my opinion the courts should be similarly cautious in extending a tort which was designed only to enforce basic standards of civilised behaviour in economic competition, between traders or between employers and labour.

In other words, a case where loss to the claimant is the obverse side of the coin from gain to the defendant. The defendant's gain and the claimant's loss are, to the defendant's knowledge, inseparably linked. The defendant cannot obtain the one without bringing about the other. If the defendant goes ahead in such a case in order to obtain the gain he seeks, his state of mind will satisfy the mental ingredient of the unlawful interference tort.

Nevertheless, the common thread is striking through a third party who might otherwise be doing business with your target, whether by buying his goods, hiring his barges or working for him or whatever. The refinement proposed by my noble and learned friend, Lord Hoffmann, is entirely consistent with the underlying principles to be deduced from the decided cases. It is also consistent with legal policy to limit rather than to encourage the expansion of liability in this area.

How any definite line is to be drawn between acts, whose real purpose is to advance the defendants' interests, and acts, whose real purpose is to injure the plaintiff in his trade, is a thing which I feel at present beyond my power. When the whole object of the defendants' action is to capture the plaintiff's business, their gain must be his loss. The defendants' success is the plaintiff's extinction and they cannot seek the one without ensuing the other.

It seems to me that Hedley Byrne, properly understood, covers this particular proposition: If a man, who has or professes to have special knowledge or skill, makes a representation by virtue thereof to another – be it advice, information or opinion – with the intention of inducing him to enter into a contract with him, he is under a duty to use reasonable care to see that the representation is correct, and that the advice, information or opinion is reliable.

In many cases, even in deceit, it will be appropriate to value the asset acquired as at the transaction date if that truly reflects the value of what the plaintiff has obtained. In many cases, even in deceit, it will be appropriate to value the asset acquired as at the transaction date if that truly reflects the value of what the plaintiff has obtained.