“3. Liability for inducing breach of contract was established by the famous case of Lumley v Gye (1853) 2 E & B 216 . The court based its decision on the general principle that a person who procures another to commit a wrong incurs liability as an accessory. As Erle J put it (at p 232): “It is clear that the procurement of the violation of a right is a cause of action in all instances where the violation is an actionable wrong, as in violations of a right to property, whether real or personal, or to personal security: he who procures the wrong is a joint wrongdoer, and may be sued, either alone or jointly with the agent, in the appropriate action for the wrong complained of.” 4. For a court in 1853, the difficulty about applying this principle to procuring a breach of contract was that the appropriate action for the wrong committed by the contracting party lay in contract but no such action would lie against the procurer. Only a party to the contract could be sued for breach of contract. The answer, said the court, was to allow the procurer to be sued in tort, by an action on the case. There was a precedent for this mixing and matching of the forms of action in the old action on the case for enticing away someone else's servant: see Gareth Jones “Per Quod Servitium Amisit” (1958) 74 LQR 39 . Some lawyers regarded that action as a quaint anomaly, but the court in Lumley v Gye treated it as a remedy of general application. 5. The forms of action no longer trouble us. But the important point to bear in mind about Lumley v Gye is that the person procuring the breach of contract was held liable as accessory to the liability of the contracting party. Liability depended upon the contracting party having committed an actionable wrong. Wightman J made this clear when he said (at p 238): “It was undoubtedly prima facie an unlawful act on the part of Miss Wagner to break her contract, and therefore a tortious act of the defendant maliciously to procure her to do so …”
“Finally, what counts as a breach of contract? In Torquay Hotel Co Ltd v Cousins[1969] 2 Ch 106 , 138 Lord Denning said that there could be liability for preventing or hindering performance of the contract on the same principle as liability for procuring a breach. This dictum was approved by Lord Diplock in Merkur Island Shipping Corporation[1983] 2 AC 570 , 607–608. One could therefore have liability for interference with contractual relations even though the contracting party committed no breach. But these remarks were made in the context of the unified theory which treated procuring a breach as part of the same tort as causing loss by unlawful means. If the torts are to be separated, then I think that one cannot be liable for inducing a breach unless there has been a breach. No secondary liability without primary liability. Cases in which interference with contractual relations have been treated as coming within the Lumley v Gye tort (like Dimbleby & Sons v National Union of Journalists[1984] 1 WLR 67 and 427) are really cases of causing loss by unlawful means.” “It is clear that the procurement of the violation of a right is a cause of action in all instances where the violation is an actionable wrong, as in violations of a right to property, whether real or personal, or to personal security: he who procures the wrong is a joint wrongdoer, and may be sued, either alone or jointly with the agent, in the appropriate action for the wrong complained of.” “It was undoubtedly prima facie an unlawful act on the part of Miss Wagner to break her contract, and therefore a tortious act of the defendant maliciously to procure her to do so …”
‘It is clear that the procurement of the violation of a right is a cause of action in all instances where the violation is an actionable wrong, as in violations of a right to property, whether real or personal, or to personal security: he who procures the wrong is a joint wrongdoer , and may be sued, either alone or jointly with the agent, in the appropriate action for the wrong complained of.’
‘It was undoubtedly prima facie an unlawful act on the part of Miss Wagner to break her contract, and therefore a tortious act of the defendant [knowingly] to procure her to do so .’
‘These statements embody an intelligible and a salutary principle, and they contain a full explanation of the law upon which the case [ Lumley v Gye ] was decided. He who wilfully induces another to do an unlawful act which, but for his persuasion, would or might never have been committed, is rightly held responsible for the wrong which he procured.’ 172. Thus understood, the rationale and the ingredients of the ‘inducement’ tort differ from those of the ‘unlawful interference’ tort. With the inducement tort the defendant is responsible for the third party's breach of contract which he procured. In that circumstance this tort provides a claimant with an additional cause of action. The third party who breached his contract is liable for breach of contract. The person who persuaded him to break his contract is also liable, in his case in tort. Hence this tort is an example of civil liability which is secondary in the sense that it is secondary, or supplemental, to that of the third party who committed a breach of his contract. It is a form of accessory liability.” ‘It is clear that the procurement of the violation of a right is a cause of action in all instances where the violation is an actionable wrong, as in violations of a right to property, whether real or personal, or to personal security: he who procures the wrong is a joint wrongdoer , and may be sued, either alone or jointly with the agent, in the appropriate action for the wrong complained of.’
‘It was undoubtedly prima facie an unlawful act on the part of Miss Wagner to break her contract, and therefore a tortious act of the defendant [knowingly] to procure her to do so .’
“The tort of inducing breach of contract is based on the wrongful interference with contractual rights. It must follow, therefore, that a person who has effected a legal assignment of his rights under a contract to a third party cannot maintain an action for interference with those rights any more than he can himself bring an action to enforce them.”
“20. In Global Resources Group v Mackay[2008] SLT 104 , Lord Hodge, then sitting in the Outer House, articulated the tort (or delict in Scotland) in these terms at paragraph 11: “A commits the delict or tort of inducing a breach of contract where B and C are contracting parties and A, knowing of the terms of their contract and without lawful justification induces B to break that contract.” 21. He went on in the following paragraphs to identify the five ingredients of the tort as being: (1) there must be a breach of contract by B; (2) A must induce B to break his contract with C by persuading, encouraging or assisting him to do so; (3) A must know of the contract and know his conduct will have that effect; (4) A must intend to procure the breach of contract either as an end in itself or as the means by which he achieves some further end; (5) if A has a lawful justification for inducing B to break his contract with C, that may provide a defence against liability”