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Conspiracy under law of torts

A conspiracy is an unlawful combination of two or more persons to do that which is contrary to law, or to do that which is wrongful and harmful towards another per- son, or to carry out an object not in itself unlawful by unlawful means.1) An actionable conspiracy exists when a number of men combine either to do an unlawful act, or to do a lawful act by unlawful means.2) It is not necessary, in order to constitute a conspiracy, that the acts agreed to be done should be acts which if done should be criminal. It is enough if the acts agreed to be done, although not criminal, are wrongful, i.e., amount to a civil wrong.3)

The essential elements, whether of a criminal or of an actionable conspiracy are the same, though to sustain an action special damage must be proved.4)

The mere act of conspiracy is not the subject of a civil action (though it may be of an indictment). There must be some act in pursuance of the conspiracy, and there must be actual damage to the plaintiff. It is the damage wrongfully done, and not the conspiracy, that is the gist of action on the case for conspiracy. Thus, where several combine to hiss an actor, or to “ boycott ” a tradesman or merchant, the element of combination is part and parcel of the wrong, since the damage could not have occurred without it. The illegal or malicious combination is then the gist of the wrong. In all such cases it will be found that there existed either an ultimate object of malice or wrong, or wrongful means of execution involving elements of injury to the public, or at least negativing the pursuit of a lawful object.5)

No action for a conspiracy lies against persons who act in concert to damage another and do damage him, but who at the same time merely exercise their own rights by lawful means and who infringe no rights of other people. Thus acts done by X and Y, who are acting in concert, solely for the purpose of protecting and extending their trade and increasing their profits, and which do not involve the employment of any means in themselves unlawful, are not actionable, even though these acts cause damage to A. In other words, trade competition carried out to an extreme length is, even though it cause damage to A, not actionable, provided that his competitors are acting solely with the lawful object of securing successes in trade and use no unlawful means.6)

While combination of different persons in pursuit of a trade object was lawful, although resulting in such injury to others as may be caused by legitimate competition in labour, yet that combination for no such object, but in pursuit merely of a malicious purpose to injure another, would be clearly unlawful.7) Where the acts complained of are in pursuance of a combination or conspiracy to injure or ruin another, and not to advance the parties' own trade interests, and injury has resulted, an action will lie. Hence, it has been unanimously held by the House of Lords in Quinn v. Leathem that a combination of two or more, without justification or excuse, to injure a man in his trade by inducing his customers or servants to break their contracts with him or not to deal with him or continue in his employment is, if it results in damage to him, actionable. A person has a right to carry on his own business, as long as he does not break the law, in the way he himself prefers. Hence, it is the legal duty of third persons not to use intimidation or coercion towards him or his customers, with a view to preventing him from carrying on his business in the way he chooses.8) This appears to be the central position finally established by the judgment of the House of Lords. The appellants in that case, namely certain trade unionists, were liable to an action, not because their motive for exercising their own rights was bad or malicious, but because they were pursuing an object which in itself was unlawful, namely, damage to A through the unjustifiable coercion and intimidation of A's customer, N, with, be it added, the further and equally unlawful, object of punishing A's servants for not having joined a trade union. This distinction between motive and object may be called a fine one, but it is a real distinction and corresponds with the dictates of common sense. It exactly differentiates the cases in which X and Y make an extreme but lawful use of their own rights whereby damage ensues to A, as in the Mogul case or in the case of the Scottish Co-operative Society v. Glasgow Fleshers Association, from Quinn v. Leathem, where the object was to do damage to A, and this object was to be attained by coercing N, i.e., interfering with N's rights.

It has often been debated whether, assuming the existence of a conspiracy to do a wrongful and harmful act towards another and to carry it out by a number of overt acts, no one of which taken singly and alone would, if done by one individual acting alone and apart from any conspiracy, constitute a cause of action, such acts would become unlawful or actionable if done by the conspirators acting jointly or severally in pursuance of their conspiracy, and if by those acts substantial damage was caused to the person against whom the conspiracy was directed : my own opinion is that they would.

In dealing with the question it must be borne in mind that a conspiracy to do harm to another is, from the moment of its formation, unlawful and criminal, though not actionable unless damage is the result.

The overt acts which follow a conspiracy form of themselves no part of the conspiracy : they are only things done to carry out the illicit agreement already formed, and if they are sufficient to accomplish the wrongful object of it, it is immaterial whether singly those acts would have been innocent or wrongful, for they have in their combination brought about the intended mischief, and it is the wilful doing of that mischief, coupled with the resulting damage, which constitutes the cause of action, not of necessity the means by which it was accomplished.

Much consideration of the matter has led me to be convinced that a number of actions and things not in themselves actionable or unlawful if done separately without conspiracy may, with conspiracy, become dangerous and alarming, just as a grain of gun-powder is harmless but a pound may be highly destructive, or the administration of one grain of a particular drug may be most beneficial as a medicine but administered frequently and in large quantities with a view to harm may be fatal as a poison.9)

That a conspiracy to injure; an oppressive combination; differs widely from an invasion of civil rights by a single individual cannot be doubted. It is said that conduct which is not actionable on the part of one person cannot be actionable if it is that of several acting in concert. This may be so where many do no more than one is supposed to do. But numbers may annoy and coerce where one may not. Annoyance and coercion by many may be so intolerable as to become actionable, and produce a result which one alone could not produce.

These observations appear to over-rule the view that a conspiracy to do certain acts gives a right of action only where the acts agreed to be done, and in fact done, would, had they been without preconcert, have involved a civil injury to the plaintiff, for which he would have had a right of action.10)

On the other hand, the judgments in Quinn v. Leathem, says a distinguished writer, tend at any rate to diminish the difference between conduct pursued by X and Y in concert and conduct pursued by X when acting without concert with others. True indeed it is that the conduct of X and Y acting in concert may be actionable whilst what may be called the same conduct when pursued by X alone is not actionable. But the reason for this distinction lies apparently far less in the absence or presence of concerted action than in the fact that there are certain kinds of damage which as a rule cannot possibly be inflicted by one person when acting without concert with others. If it should happen that one man, X, could not by means of conspiracy, but through his extensive power and influence, work the same kind of damage to A which can in general be achieved only by the combined efforts of X, Y and Z, it is quite possible that X might be liable to an action.

Lord Lindley says : “ It was contended that if what was done in this case had been done by one person only, his conduct would not have been actionable, and that the fact that what was done was effected by many acting in concert makes no difference. One man without others behind him who would obey his orders could not have done what these defendants did. One man exercising the same control over others as these defendants could have acted as they did, and, if he had done so, I conceive that he would have committed a wrong towards the plaintiff for which the plaintiff could have maintained an action.

From the main principle, however, of Quinn v. Leathem flow three subordinate conclusions which may be treated as certain, and may be practically as important as the main point decided by the judgment of the House of Lords. These subordinate points may be thus stated:

  1. Lumley v. Gye, Bowen v. Hall and Temperton v. Russell were rightly decided and are good law at any rate to this extent; that if without legal justification X induces N to break a contract with A, who suffers damage thereby, or if X by means of coercion or molestation or threats thereof compels N to cease dealing with or remaining in the employment of A who is damaged thereby, X is liable to an action by A, and this is so even though N, e. g., in ceasing to deal with A, does not break any contract with A.
  2. The term coercion or intimidation includes threats not only of bodily harm but also of serious annoyance and damage.
  3. The Conspiracy and Protection of Property Act, 1875, s. 3, has nothing to do with civil remedies, and the term 'trade dispute between employers and employed' does not include such a transaction as that with which the Courts were called upon to deal in Quinn v. Leathem.

Plaintiff, being about to become an actor, the defendants, with other persons, maliciously conspired to prevent him from exercising that profession. They, in pursuance of such conspiracy, hired persons to hiss, and who accordingly attended the theatre for that purpose. The plaintiff appeared in character upon the stage, and thereupon the defendants, with other persons, hissed and hooted the plaintiff, so as to compel him to desist from the performance and thereby caused the plaintiff to lose his engagement. Held, that a good cause of action was shown (Gregory v. Brunswick, 6 M.& G. 205). A combination between shipowners carrying from the same ports, with the object of keeping freights within their control, effected by allowing a rebate to shippers who ship exclusively on board their ships, by prohibiting their agents, on penalty of removal, from being directly or indirectly interested in ships other than theirs, and by sending to ports where other shipowners are asking for cargo, ships sufficient to lower the freights below the rate under open competition, thereby causing loss to such shipowners, not being attended by circumstances of dishonesty, intimidation, molestation. Of actual malice, is not actionable as a wrong by individuals, as a conspiracy, or as in restraint of trade.11) An action will not lie against persons who, for their own benefit, combine to induce others to refrain from dealing with a particular person .12)

Defendants were members of a joint committee of three trade unions. A firm of builders having refused to obey certain rules laid down by the unions with regard to the building operations, the unions sought to compel them to do so, by preventing the supply of building materials to them. They, therefore, requested the plaintiff, who supplied building materials to the firm, to cease to supply them with such materials but the plaintiff refused to do so. Thereupon, with the object of injuring the plaintiff in his business, in order to compel him to comply with such request, the defendants induced persons who had entered into contracts with the plaintiff for the supply of materials, to break their contracts, and not to enter into further contracts with the plaintiff, by threatening that the workman would be withdrawn from their employ. The plaintiff sustained damage in consequence of such breaches of contracts, and of the refusal of such persons to enter into contracts with him. Held, that an action was maintainable by the plaintiff against the defendants for maliciously procuring such breaches of contracts, and also for maliciously conspiring together to injure him by preventing persons from entering into contracts with him.13)

The respondents were shipwrights employed “for the job” on the repairs to the woodwork of a ship, but were liable to be discharged at any time. Some ironworkers who were employed on the ironwork of the ship objected to the respondents being employed, on the ground that the respondents had previously worked at ironwork on a ship for another firm, the practice of shipwrights working on iron being resisted by trade union of which the iron- workers were members. The appellant, who was a delegate of the union, was sent for by the ironworkers and informed that they intended to leave off working. The appellant informed the employers that unless the respondents were discharged all the ironworkers would be called out or knock off the work (it was doubtful which expression was used); that the employers had no option; that the iron-men were doing their best to put an end to the practice of shipwrights doing ironwork and that wherever the respondents were employed the ironmen would cease work. There was evidence that this was done to punish the respondents for what they had done in the past. The employers, in fear of this threat being carried out which would have stopped their business, discharged the respondents and refused to employ them again. The respondents brought an action against the appellant. Held, that the appellant had violated no legal right of the respondents, done no unlawful act, and used no unlawful means, in procuring the respondents' dismissal; that his conduct was not actionable however malicious or bad his motive might be.14)

The plaintiffs were manufacturers of leather bags. The defendants were the secretary and a member of the executive committee of a trade union. The union had ordered a strike against the plaintiffs partly for an increase of wages and partly to put an end to the system of paying some persons by piece work and some by time. The union had picketed the plaintiffs, and had also ordered a strike against another maker who made only for the plaintiffs. The plaintiffs alleged that one letter, written as part of the trade-contest to an employee, amounted to a libel, and that a workman had been induced by the union to break his contract, and that the acts of the plaintiffs in trying to induce people not to enter their employment was malicious. The Court granted an injunction to restrain the defendants from maliciously inducing persons not to enter into the employ of the plaintiffs.15) The plaintiff entered into a contract by which he was apprenticed to his employers to learn certain work. A friendly society of workmen engaged in similar work protested to the employers against the engagement of the plaintiff as an apprentice, on the ground that it was a breach of one of the rules of the society which the employers had agreed to and signed, and they gave notice that, if the engagement was continued, they would call out the workmen who were working for the employers, and who were all members of the society. In consequence of this threat the employers refused to continue to teach the plaintiff under the terms of the deed of apprenticeship. In an action by him against the society and certain of the officers, it was held that he had a good cause of action to which the previous agreement between the society and the employers was no answer.16) The executive council of a coal miners trade union were authorized by the members to declare a general holiday at any time they might think it necessary for the protection of wages and of the industry generally in order to arrest the downward price of coal. The council subsequently declared a general holiday, without notice to the masters, when all the miners left off work for the day. In doing so, the council acted from an honest desire to forward the interests of the men having been solicited by the men to advise and guide them on the point, and not from a desire to injure the masters, and without any malice towards them. In an action by the masters against the trade union for wrongfully and maliciously inducing the men to break their contracts of service, it was held that the council had lawful justification or excuse for what they did, and that the action was not maintainable.17) In a case of intimidation by trades' unionists, an injunction was granted against issuing placards enjoining workmen not to work for the plaintiff until the dispute between the plaintiff and the trade union was settled, on the ground that the act of such unionists tended to the destruction or deterioration of the plaintiff's property.18)

Indian case: A mere conspiracy to injure a man without an overt act resulting in the injury does not furnish any cause of action. A conspiracy is not illegal unless it results in an act done which by itself would give a cause of action.19)


Conspiracy is

  1. an unlawful combination of two or more persons to injure a third party, or
  2. a combination to injure but without the use of unlawful means.20)


The concept of conspiracy originated during the days of the “Star Chamber” in England as a crime, later the Common Law courts made it a civil wrong. The leading cases are Crofter v. Veitch, Allen V. Flood, Quinn V. Leathern, Moghul Steamship Co. V. Me Gregor, and Sorrell V. Smith.


  1. The purpose must be to cause damage to the plaintiff.
  2. Combination of persons.
  3. Overt act of causing damage.


“Intention” or “Malice” is not the essential ele-ment. What is required is that the defendants should have acted in order that the plaintiff should suffer damage. Hence, the main purpose or objective decides whether there is conspiracy or not.

Crofter V. Veith : 7 small producers of tweed were using imported yarn to make cloth. 5 mill owners were using local yarn to manufacture cloth and they could sell at cheaper rates. The union of mills desired to fix a minimum price for cloth. Their objective was to get their wages increased. They could not get higher wags as the 7 small tweed producers were paying less. The union officials put an embargo on importation of yarn by ordering the dock-workers no to handle import yarn. This was obeyed by them. In consequence the small producers suffered and their trade was affected. They sued for conspiracy. Held, union is not liable. The main purpose was not to affect trade but to promote their own interests.

In Moghul Steamship Co. v Me Gregor, the defendants offered reduced freight charges to gain a monopoly of the China Tea trade. P, a shipping company seriously suffered which sued for conspiracy. Held, not liable. The main object of the defendants was to earn profits. This was usual in a business competition.21)

Quinn V. Leathern : P was a butcher selling a good quantity of meat to a big dealer M. The defendants D, the union officials, demanded that P should dismiss his workers and appoint only the members of the union. P refused. D induced M to stop buying from P with a threat that if M does not obey, his workers (who were members of the union) would resort to strike. M stopped all dealings with P. P suffered and sued for conspiracy. Held, defendants liable. The purpose in effect was to affect the business of P.

Sorrel V. Smith: Retail Newspaper formed a union, and de-sired to limit the shops only to themselves and those who had union’s permission. R was a wholesale dealer who supplied newspapers to a few retailers who had opened shops without union’s permission. The union interfered. It transferred P the customer of R to another wholesaler W. The newspapers owners, the defendants, found this to be injurious to trade and jointly they threatened to stop supplies to W. P sued the defendants, to restrain them from stopping. Held, no order or injunction against D was to be given. The combination was not to injure W or others but only to protect the interests of the newspaper trade.

Combination of persons

There must be two or more persons with the objective or purpose to injure a third person. The nature of the purpose is evident from the above cases.

Over act

There must be an overt act to cause damage in addition to the combination of persons. Mere overt act by itself will not be actionable injury. This is evident from Mighell V. Me Gregor and Sorrel V. Smith. The act must be injurious to trade as in Quinn V. Leatham.

1) , 4) , 7) , 8) , 9)
Quinn v. Leathem
2) , 17)
Glamorgan Coal Co. v. South Wales Miners Federation
R. v. Warburton
Mogul Steam S. Co. v. M'Gregor
Mogul Steamship case
Huttley v. Simons
Mogul Steamship Co. v. M'Gregor
Boots Cash Chemists v. Grundy
Temperton v. Russell and others
Alien v. Flood and Taylor
Lyons v. Wilkins
Read v. Friendly Society
Springhead Spinning Co. v. Riley
Templeton v. Laurie
Allen V. Flood

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