Economic Torts

Civil Conspiracy

Civil Conspiracy n. [Legal usage; from Latin conspirare, "to plot or act in harmony"]

An agreement or combination between two or more persons to act together for the purpose of causing harm to another, whether by lawful or unlawful means, resulting in actual damage. Civil conspiracy is recognized as a tort when the conduct leads to loss or injury.

Grigoras Law represents clients across Ontario in civil conspiracy matters involving coordinated conduct designed to cause economic harm. We handle claims and defences in cases of unlawful means conspiracy, lawful means conspiracy with predominant purpose to injure, and multi-party commercial wrongdoing. Our work includes proving or challenging the existence of agreements, establishing intent and predominant purpose, coordinating with related economic tort claims, and pursuing or defending against claims for damages and injunctive relief.

What We Do

Civil Conspiracy Services

Predominant Purpose Conspiracy Claims

Actions where lawful conduct becomes tortious due to malicious intent to injure. We prove agreement, predominant purpose to harm, and resulting damage where conspirators' main objective is economic injury.

Jump to section

Unlawful Means Conspiracy Actions

Claims where unlawful conduct directed at the plaintiff causes economic harm. We establish agreement, prove means were directed at you, demonstrate unlawfulness, and show constructive intent to injure.

Jump to section

Agreement & Intent Analysis

Evidence gathering to prove coordinated action and malicious purpose. We build cases through direct and circumstantial evidence, including communications, parallel conduct, and patterns suggesting common plans.

Jump to section

Multi-Party Dispute Strategy

Complex litigation involving multiple conspirators, corporations, directors, and third parties. We navigate corporate law principles, determine which parties to join, and coordinate concurrent tort claims.

Jump to section

Defence Against Conspiracy Claims

Defence strategies including justification, statutory labour defences, challenging existence of agreement, proving lack of malicious intent, and establishing legitimate business activities.

Jump to section

Causation & Damages Recovery

Proving the conspiracy caused financial loss and quantifying damages. We establish causal links, provide expert economic analysis, seek compensatory and punitive damages, and pursue injunctive relief.

Jump to section

Your Legal Team

Your Civil Conspiracy Counsel

Denis Grigoras

Denis Grigoras

Counsel, Civil & Appellate Litigation

  • Unlawful means conspiracy and lawful means conspiracy with predominant purpose to injure
  • Multi-party coordination claims involving breach of contract, inducing breach, and interference
  • Proving agreements through circumstantial evidence and parallel conduct analysis
  • Predominant purpose assessment and intent to injure evidence strategies
  • Joint and several liability frameworks and contribution claims between co-conspirators
View Profile
Rachelle Wabischewich

Rachelle Wabischewich

Counsel, Civil & Appellate Litigation

  • Civil conspiracy defence: challenging agreement element and predominant purpose claims
  • Concurrent tort coordination: conspiracy paired with defamation, breach of confidence, passing off
  • Evidentiary strategy for proving or disproving concerted action between alleged conspirators
  • Damages assessment in multi-defendant conspiracy cases and apportionment issues
  • Injunctive relief applications to restrain ongoing conspiracies and prevent further harm
View Profile

Representative Work

Selected Civil Conspiracy Matters

  • Multi-party cannabis investment fraud conspiracy

    Investment Fraud

    Ontario Superior Court of Justice · Cannabis sector

    Represented investor in action against multiple corporate and individual defendants accused of conspiring to defraud through misrepresentations about cannabis cultivation facilities. Claims included unlawful means conspiracy, corporate veil piercing, fraudulent misrepresentation, and oppression remedy. Case involved alleged diversion of investor funds for unauthorized purposes and coordination among family-controlled entities to defeat creditor claims.

  • Real estate development conspiracy and fraudulent conveyance

    Fraudulent Transfer

    Ontario Superior Court of Justice · Real estate development and family business

    Represented plaintiffs in action against defendant accused of conspiring with controlling shareholder to strip assets from development companies through fraudulent transfers. Claims included civil conspiracy, conversion, breach of fiduciary duty, and corporate veil piercing. Case involved allegations of orchestrated transfers of real property and corporate funds to defeat outstanding creditor claims while defendant maintained lavish lifestyle through corporate resources.

Understanding Civil Conspiracy

What is Civil Conspiracy?

Civil conspiracy is a common law tort that holds multiple parties liable when they agree to act together in a way that causes economic harm to another. The term derives from the Latin conspirare, meaning "to breathe together," reflecting the core concept of coordinated wrongdoing. Unlike other economic torts discussed in this guide, conspiracy requires proof of an agreement between two or more people—acting alone, the same conduct might not attract liability.

What makes conspiracy unusual is that it is not simply joint tortfeasance. As the UK Supreme Court explained in JSC BTA Bank v. Ablyazov, conspiracy is a distinct tort with primary liability. The fact of combination can alter the legal character of acts that would be lawful if done individually. In other words, plurality itself can convert otherwise permissible conduct into tortious conduct.

Canadian courts recognize civil conspiracy as an established cause of action, though its scope and rationale have been subject to judicial scrutiny. The tort protects against coordinated economic harm, whether inflicted through lawful or unlawful means, and serves as a check on concerted conduct designed to injure business interests.

Historical Development and Purpose

Civil conspiracy has medieval origins. It began as an action providing civil redress where two or more persons combined to abuse the court's criminal process. Over time, the writ evolved into an action on the case and flourished in the nineteenth century, largely as a judicial tool to regulate activities by organized labour and rival entrepreneurs.

The tort developed differently in Commonwealth jurisdictions than in the United States. American courts remained skeptical of the premise that mere numbers could convert lawful conduct into unlawful conduct. Many U.S. jurisdictions rejected civil conspiracy entirely or adopted it only in narrow forms. Instead, American law developed independent doctrines such as unfair competition and the prima facie tort doctrine, which provide courts with broader remedies not dependent on combination.

In contrast, English and Commonwealth courts embraced conspiracy to regulate industrial and commercial disputes and to reinforce laissez-faire economic principles. The classic articulation came in Mogul Steamship Co. v. McGregor, Gow and Co., where Bowen L.J. explained that combination may make "oppressive or dangerous that which if it proceeded only from a single person would be otherwise." This rationale achieved the status of judicial dogma, despite mounting criticism.

The House of Lords in Lonrho Ltd. v. Shell Petroleum Co. (1981) questioned this foundation. Lord Diplock observed that to suggest acts done by one street-corner grocer in concert with a second are more oppressive than acts by a chain of supermarkets under single ownership is to ignore modern economic realities. Nevertheless, the court retained predominant purpose conspiracy because it was too deeply embedded in precedent to be reversed.

Canadian law followed a parallel evolution. The Supreme Court of Canada in Canada Cement LaFarge Ltd. v. British Columbia Lightweight Aggregate Ltd. acknowledged conspiracy as a judicial anachronism but concluded it was too late to uproot it from the common law. The court instead refined the tort's elements to require either predominant purpose to injure or constructive intent derived from unlawful means directed at the plaintiff.

Two Varieties of Conspiracy

Modern Canadian law recognizes two forms of civil conspiracy, terminology clarified by the Supreme Court in Pro-Sys Consultants Ltd. v. Microsoft Corp.:

  • Predominant Purpose Conspiracy: Liability arises when two or more persons agree to engage in conduct (lawful or unlawful) where the predominant purpose is to injure the plaintiff, and damage results. The tortious quality stems from the fact of acting together with this malicious purpose, not from the means used.
  • Unlawful Means Conspiracy: Liability arises when two or more persons agree to engage in unlawful conduct directed at the plaintiff, injury is foreseeable, and damage results. Here the tortious quality stems from both the unlawful means and the fact of combination. Injury need not be the predominant purpose, but there must be at least constructive intent to harm.

The distinction is crucial. Predominant purpose conspiracy can be committed using entirely lawful means, provided the conspirators' main objective is to harm the plaintiff. This is an anomaly—it makes combination itself wrongful when accompanied by malicious intent. Unlawful means conspiracy, by contrast, requires unlawful conduct but does not require that harming the plaintiff be the main objective. The unlawfulness of the means, combined with their being directed at the plaintiff, supplies the tortious element.

Both varieties ultimately protect economic interests from intentional wrongdoing. The tort reinforces market integrity by discouraging the misuse of concerted action for anti-competitive purposes or to inflict deliberate economic harm.

Elements of the Tort

Predominant Purpose Conspiracy Elements

To succeed in a claim for predominant purpose conspiracy, the plaintiff must prove:

  1. An agreement between two or more persons to engage in conduct (whether lawful or unlawful);
  2. The predominant purpose of the agreement is to injure the plaintiff; and
  3. The plaintiff suffers damage as a result.

This form of conspiracy is unusual because it renders otherwise lawful conduct actionable based solely on the conspirators' malicious intent. The rationale is that coordinated action motivated by a desire to harm, rather than to advance legitimate interests, is inherently wrongful.

Unlawful Means Conspiracy Elements

To succeed in a claim for unlawful means conspiracy, the plaintiff must prove:

  1. An agreement between two or more persons to engage in conduct;
  2. The conduct is directed at the plaintiff (alone or together with others);
  3. The means employed are unlawful; and
  4. The defendants should know in the circumstances that injury to the plaintiff is likely to result, and damage does result.

As articulated in Canada Cement LaFarge, this form requires "constructive intent" to injure—the defendants must have known or ought to have known that their unlawful conduct would harm the plaintiff. Predominant purpose to injure is not necessary, but the unlawful means must be directed toward the plaintiff, not merely incidental to some other objective.

Predominant Purpose Conspiracy

Agreement Between Two or More

The foundation of conspiracy is an agreement. As stated in Mulcahy v. The Queen, "a conspiracy consists not merely in the intention of two or more, but in the agreement of two or more." The agreement constitutes a joint plan or common design and need not amount to a legally enforceable contract.

Individual defendants are liable only if they intentionally participate in the agreement. Mere knowledge of or acquiescence in the conspiracy is insufficient. Making an agreement is not the same as simply "being in agreement"—directors who all vote the same way at a meeting are not thereby conspiring unless they entered into a compact in advance.

Although direct evidence of an agreement is preferred, conspiracy can be established by inference from circumstantial evidence, provided the facts cannot fairly admit any other reasonable explanation. The law recognizes that conspirators rarely document their schemes. Evidence of parallel conduct, coordinated timing, common interests, and communication between alleged conspirators may support an inference of agreement.

An overt act in furtherance of the agreement is required—unlike criminal conspiracy, the civil tort is not complete until the conspirators take steps to execute their plan and damage results. Pleadings must specify the overt acts and attribute them to the appropriate defendants.

Corporations can be parties to conspiracies. A company can conspire with its directors since a corporation is a separate legal entity. Servants and agents acting on an employer's instructions may also be parties to a combination if they "appreciated what they were about." A parent company can conspire with its subsidiary in appropriate circumstances.

Trade unions, as separate entities, are not vicariously liable for member conduct absent statutory authority. To establish union liability, the plaintiff must show the union itself agreed through its officers to commit unlawful acts or directed members to do so.

The question whether spouses can conspire together remains open in civil conspiracy, as the criminal law presumption of unity of will may not apply where the gist is economic damage rather than public order concerns.

Purpose to Injure the Plaintiff

The leading authority on this element is Crofter Hand Woven Harris Tweed Co. v. Veitch. In that case, union officials instructed dockers to refuse handling the plaintiff's yarn, causing economic loss. The House of Lords held the conspiracy was not actionable because the predominant purpose was promoting the union's legitimate self-interest, not injuring the plaintiff.

Several principles emerge from Crofter and subsequent cases:

  • The test focuses on the true purpose or object of the combination, not the natural or probable result of the defendants' actions.
  • "Object" means the ultimate end or goal. It is distinguished from "motive" or "immediate purpose."
  • Where multiple objects exist, liability depends on the predominant object.
  • A conspiracy whose predominant object is to injure the plaintiff is unlawful.
  • If the predominant object is to advance the conspirators' legitimate self-interest, the combination is lawful.
  • Self-interest is not limited to trade or business interests; trade union interests and other legitimate objectives may qualify.

The burden of proof lies with the plaintiff to establish the unlawful object. The defendant need not justify their conduct until the plaintiff proves that injury to the plaintiff was the predominant purpose. This differs from the view that combination to cause intentional damage is prima facie actionable absent justification—the better analysis treats predominant purpose to injure as an essential element the plaintiff must prove.

Courts examine the defendants' actual purpose, which may be inferred from their conduct and the factual circumstances. The inference that persons intend the natural and probable consequences of their actions may assist in determining intent, but it is not conclusive. Defendants whose primary aim is self-advancement do not commit this tort merely because they foresee harm to a competitor.

Unlawful objects beyond injury to the plaintiff may exist. Examples include demonstration of power by busybodies, dislike based on race, religion, or political views, and acceptance of bribes. Modern courts would recognize that objectives rooted in discrimination or corruption fall outside legitimate self-interest and constitute unlawful purposes.

Trade union cases have generated significant case law. Canadian courts have found unions liable where the predominant purpose was found to be punishing the plaintiff rather than advancing union members' interests. For instance, in Dusessoy's Supermarkets St. James Ltd. v. Retail Clerks Union, Local 832, the court concluded that the union's stated motives were "a cloak" for an intention to bring the plaintiff to its knees. Similarly, in Moffat Communications Ltd. v. Hughes, secondary picketing was found to constitute conspiracy where the predominant purpose was to injure the plaintiff rather than protect union interests.

Damage to the Plaintiff

An agreement with a predominant purpose to injure is not itself actionable. The defendants must perform overt acts pursuant to the agreement that cause actual damage to the plaintiff. Damage is the gist of the civil action for conspiracy—without it, no tort is complete.

The contentious question is whether the plaintiff must prove pecuniary loss or whether non-pecuniary harm suffices. In Shaw v. Lewis, the British Columbia Court of Appeal held that invasion of a legal right done in combination by unlawful means is actionable without proof of pecuniary damage. However, in Valley Salvage Ltd. v. Molson Brewery B.C. Ltd., the court distinguished Shaw and held that where injury to business is claimed, actual pecuniary loss must be shown.

The English Court of Appeal in Lonrho plc. v. Fayed (No. 5) unequivocally held that predominant purpose conspiracy requires proof of actual pecuniary loss. The court noted that once pecuniary loss is established, damages are at large, but the loss must be related to the tortious conduct. Damage for loss of reputation or feelings cannot be recovered.

Canadian law remains somewhat unsettled on this point, though the weight of authority suggests pecuniary loss is required at least in commercial conspiracy cases. Once established, damages are at large in the sense that specific quantification of each element of loss is not necessary. Aggravated and exemplary damages may be awarded where the conduct warrants such relief.

Unlawful Means Conspiracy

Agreement Between Two or More

The same principles governing agreements in predominant purpose conspiracy apply to unlawful means conspiracy. However, an additional requirement exists: the alleged conspirators must be aware that their agreed conduct is unlawful. It is insufficient for the agreement to relate to conduct that happens to be unlawful if the defendants did not know it to be so.

As stated in Nicholls v. Richmond (Township), where defendants fully intended to fulfill legal obligations and did not intend to commit a tort or breach contract, no conspiracy lies. Ignorance or mistake of law is relevant in negating the agreement element. The burden of proving lack of knowledge falls on the defendants once a prima facie case is established.

This requirement was challenged in Racing Partnership Ltd. v. Done Bros. (Cash Betting) Ltd., where the English Court of Appeal (by majority) held that knowledge of unlawfulness is not an essential element of unlawful means conspiracy. The dissenting judge argued that where unlawful means consist of violation of private rights, knowledge should be required. The case is under appeal to the UK Supreme Court.

If the majority view prevails, acting in combination to injure the plaintiff's interests by means reasonably believed to be legal, with the predominant purpose of advancing one's own interests, would nevertheless be tortious if the means prove unlawful. This would expand liability significantly and blur the distinction between the two varieties of conspiracy.

Canadian courts have not directly addressed this issue post-Racing Partnership. The better view, consistent with requiring constructive intent, is that defendants should at minimum be reckless as to the lawfulness of their means—wilful blindness or deliberate ignorance would suffice, but reasonable but mistaken belief in legality should not attract liability.

Means Directed at the Plaintiff

The Supreme Court of Canada fundamentally reshaped unlawful means conspiracy in Canada Cement LaFarge Ltd. v. British Columbia Lightweight Aggregate Ltd. The defendants were major cement producers found to have violated competition law by conspiring to drive out competitors. The plaintiff, a supplier of aggregate to the cement industry, claimed damages.

Although the defendants' conduct was clearly unlawful (breach of the Combines Investigation Act), the Supreme Court held no liability existed because the conspiracy was not directed at the plaintiff. The defendants' anticompetitive agreement targeted consumers by keeping concrete prices high. Any harm to the plaintiff, an aggregate supplier, was collateral and incidental—not part of the conspiracy's objectives.

Justice Estey formulated the modern Canadian test: unlawful means conspiracy requires that the unlawful conduct be "directed towards the plaintiff" and that "the defendants should know in the circumstances that injury to the plaintiff is likely to and does result." This imports a requirement of constructive intent to injure, derived from the fact that defendants should have known injury would ensue.

English courts adopted a similar approach in Revenue and Customs Commissioners v. Total Network SL and JSC BTA Bank v. Ablyazov. Both cases emphasize that all actionable conspiracies are conspiracies to injure, though the intent required may take various forms. In unlawful means conspiracy, intent to injure need not be predominant, but it must be present—the unlawful means must be "the instrument for the intentional infliction of harm."

In Lonrho (1981), the oil companies' breach of sanctions against Rhodesia may have been foreseeable harm to the plaintiff's pipeline business, but that consequence was irrelevant to the conspiracy's objective, which was protecting the defendants' own interests. The breach was not directed at harming the plaintiff; harm was merely a side effect.

By contrast, in Total Network, fraud on the revenue was aimed directly at causing loss to the tax authorities. In Ablyazov, breaches of court orders were the means by which the conspirators kept assets from the plaintiff bank. In both cases, the unlawful means were the very instrument of harm to the plaintiff.

This "directed at" requirement distinguishes unlawful means conspiracy from broader liability for economic harm. Plaintiffs cannot simply point to unlawful conduct that incidentally harms them; they must show the unlawful means were deployed with at least constructive knowledge that injury would result and that the plaintiff was within the intended target of the scheme.

The Unlawful Means

"Unlawful means" has different definitions across economic torts. The Supreme Court of Canada observed in A.I. Enterprises Ltd. v. Bram Enterprises Ltd. that there is no general requirement of consistency. In unlawful means conspiracy, the term is broader than in the tort of causing loss by unlawful means, where actionability by a third party is required.

Unlawful means in conspiracy includes:

  • Independent torts: Inducing breach of contract, interference with contractual relations, nuisance, intimidation, defamation, and other actionable civil wrongs.
  • Breach of contract: While debated, breach of contract may constitute unlawful means, particularly where it interferes with the plaintiff's economic interests.
  • Criminal offences: Breach of the Criminal Code, including extortion, fraud, and other indictable offences.
  • Statutory violations: Breach of regulatory statutes even where no private right of action exists, such as labour relations legislation or competition law.
  • Contempt of court: As held in Ablyazov, breach of court orders can constitute unlawful means despite being penal in nature.

Lord Dunedin observed in Sorrell v. Smith that alleging conspiracy where tortious acts are committed is "mere surplusage." However, framing a claim in conspiracy offers advantages: it may capture instigators who did not directly participate in the tort, it may support aggravated damages, and it provides evidentiary benefits (statements by co-conspirators are admissible against all).

The categories of unlawful means are not closed. Courts have recognized that conduct comprising regulatory violations, competition law breaches, and even statutory conspiracy itself can support a civil conspiracy claim. In the trial and Court of Appeal decisions in Canada Cement LaFarge, breach of competition law was held sufficient, though the Supreme Court decided the case on causation grounds without resolving the point definitively.

Whether contemplated unlawful acts alone (without execution) support an action remains unclear. The classic definition suggests an agreement to do an unlawful act per se is actionable, but most cases require actual use of unlawful means. The better view is that an agreement to commit unlawful acts is actionable only under predominant purpose conspiracy unless and until the unlawful means are actually employed.

Damage to the Plaintiff

As with predominant purpose conspiracy, damage is the gist of the unlawful means tort. The same debate exists regarding whether pecuniary loss must be proven or whether non-pecuniary harm suffices.

Shaw v. Lewis, an unlawful means conspiracy case, held pecuniary loss was unnecessary. Valley Salvage took the opposite view for business injury claims. The English decision in Lonrho plc. v. Fayed (No. 5), also involving unlawful means conspiracy, firmly held that pecuniary loss is required.

Given that unlawful means conspiracy protects primarily economic interests, the weight of authority supports requiring pecuniary loss at least in commercial contexts. Non-pecuniary rights (such as membership in organizations or personal dignitary interests) may be protected without pecuniary loss in limited circumstances, but courts require clear demonstration that the legal interest invaded is one the tort is designed to protect.

Once pecuniary loss is established, damages are at large and may include consequential losses flowing from the conspiracy. Aggravated and punitive damages may be awarded where the defendants acted with a high degree of malice or in flagrant disregard for the plaintiff's rights.

Defences and Limitations

Statutory Defences

Several Canadian provinces have enacted legislation excluding civil actions against unions or their members for interference with contracts or trade arising from lawful strikes, picketing, or labour disputes, provided statutory conditions are met. These provisions offer an effective defence to conspiracy claims in the labour context.

For example, British Columbia's Labour Relations Code specifically excludes liability for petty trespass, interference with contractual relations, or interference with trade arising from lawful strikes or picketing. Ontario and Saskatchewan legislation bars actions for breaches of statutes not actionable in themselves when committed in contemplation or furtherance of a trade dispute.

These defences do not extend to independently tortious acts. If the conspiracy involves conduct that is both unlawful and actionable absent combination (such as assault, defamation, or fraud), statutory protection does not apply. Similarly, illegal strikes or picketing that violates statutory requirements fall outside the protection.

Courts have also held that where parties agree to arbitrate disputes under collective agreements, resort to conspiracy claims may be barred by the arbitration clause. The policy favoring labour arbitration as the primary dispute resolution mechanism may preclude tort actions arising from the same facts.

Justification and Self-Interest

In predominant purpose conspiracy, advancing legitimate self-interest is not technically a "defence" but rather negates an essential element of the tort. If the defendants' predominant purpose was to further their own lawful interests rather than to injure the plaintiff, no unlawful object exists and the tort is not made out.

Self-interest encompasses trade and business interests, union interests, and potentially other legitimate objectives. The test is whether the predominant purpose was self-advancement. Courts do not generally inquire into the reasonableness of the defendants' belief that their actions would serve their interests, though the interests themselves must be "legitimate."

"Legitimate" likely means lawful rather than reasonable. An illegal strike, for instance, does not advance a union's legitimate interests. Interests rooted in discrimination, corruption, or malice (such as racial animus or acceptance of bribes) are not legitimate even if they serve some personal end.

In unlawful means conspiracy, justification is not available as a defence. The Supreme Court in Canada Cement LaFarge confirmed that once unlawful means directed at the plaintiff with constructive intent are established, the fact that defendants' predominant purpose was self-advancement does not excuse liability. This follows from the nature of the tort: if the means are unlawful and aimed at the plaintiff, the law provides no safe harbor based on mixed motives.

The doctrine of ex turpi causa non oritur actio (no action arises from one's own wrongdoing) may defeat a conspiracy claim by a participant in the conspiracy who later suffers injury. As recognized in Canada Cement LaFarge, a party who participated in a conspiracy cannot subsequently claim damages arising from that participation. This prevents plaintiffs from profiting from their own illegal conduct.

Litigation Strategy

Evidence Requirements

Civil conspiracy claims require careful evidence gathering to establish each element. Unlike single-party torts, conspiracy demands proof of coordinated action, which is rarely documented explicitly. Plaintiffs must build their case through direct and circumstantial evidence.

Agreement: Direct evidence (written agreements, recorded conversations, testimony from participants) is ideal but rare. More commonly, plaintiffs rely on circumstantial evidence: parallel conduct by alleged conspirators, meetings or communications between them, common financial interests, coordinated timing of actions, and patterns suggesting a common plan. Courts require that the inference of agreement be the only reasonable explanation for the facts proven.

Purpose or intent: For predominant purpose conspiracy, plaintiffs must prove the defendants' true objective. Evidence may include statements of intent, documents revealing motivation, the natural consequences of the defendants' actions, and the absence of legitimate business justification. Expert evidence on industry practices may help show whether the conduct serves any legitimate purpose. Defendants' own explanations for their conduct, if internally inconsistent or contradicted by their actions, may support an inference of malicious intent.

For unlawful means conspiracy, constructive intent must be shown—that defendants knew or should have known their unlawful conduct would harm the plaintiff. Evidence showing the defendants understood the nature of their conduct, its likely effects, and the plaintiff's vulnerability strengthens the case.

Unlawful means (for unlawful means conspiracy): Documentary evidence of statutory violations, criminal activity, tortious conduct, or breach of contract is essential. Regulatory findings, criminal convictions, or prior civil judgments may be admissible. Evidence showing defendants knew or should have known their conduct was unlawful supports the agreement element.

Causation and damages: Plaintiffs must prove the conspiracy caused their loss. Financial records, lost contracts, expert testimony on market conditions, and evidence of the plaintiff's business trajectory before and after the conspiracy are typical. Where multiple factors may have contributed to the loss, careful economic analysis is required to isolate the harm attributable to the conspiracy.

A special evidentiary rule applies: statements by one conspirator made during the conspiracy and in furtherance of its objectives are admissible against all co-conspirators. This rule, borrowed from criminal law, can be powerful but requires the court first find sufficient evidence of the conspiracy to warrant applying the rule.

Strategic Considerations

Civil conspiracy claims often arise alongside other economic torts. Counsel must consider whether to plead conspiracy alone or in combination with inducing breach of contract, interference with economic relations, defamation, intimidation, or causing loss by unlawful means. Each tort has distinct elements and advantages.

Advantages of pleading conspiracy:

  • Captures multiple defendants in a single cause of action
  • May hold liable instigators and planners who did not personally commit overt tortious acts
  • Aggravated and punitive damages may be more readily available
  • Evidentiary advantages (co-conspirator statements)
  • May overcome defences available to individual tort claims

Challenges in conspiracy claims:

  • Higher burden of proof (must prove agreement, not just parallel conduct)
  • Predominant purpose conspiracy requires proving malicious intent, which defendants can refute by showing self-interested motives
  • Unlawful means conspiracy requires proving both unlawfulness and that means were directed at plaintiff
  • Risk that failure to prove conspiracy undermines the entire case if it is the sole cause of action

Defendants facing conspiracy allegations should:

  • Challenge the existence of any agreement (emphasize independent decision-making)
  • Establish legitimate business justifications for conduct (self-interest defence in predominant purpose conspiracy)
  • Demonstrate that unlawful means, if any, were not directed at the plaintiff or that harm was unforeseeable
  • Argue lack of knowledge that means were unlawful
  • Prove statutory defences where available (labour relations context)
  • Attack causation and quantum of damages

Pleadings must be specific. Courts require plaintiffs to identify the alleged conspirators, describe the agreement with particularity, specify the overt acts committed in furtherance of the conspiracy, and attribute specific acts to specific defendants. Vague or conclusory allegations may be struck out.

In multi-party commercial disputes, conspiracy claims can be especially complex. Where some defendants are corporations, others are directors or officers, and still others are third parties, careful attention to corporate law principles (separate legal personality, piercing the veil, deemed directors) is essential. Establishing that a corporation can conspire with its own directors or that a parent conspired with a subsidiary requires navigating these doctrinal issues.

Early legal advice is critical. The tort's subtleties—particularly the distinction between the two varieties and the interplay with other economic torts—demand strategic thinking from the outset. Whether to pursue interim injunctive relief, how to preserve evidence of the agreement, and whether to join all potential conspirators or proceed against a subset are threshold decisions that shape the entire litigation.

Common Questions

F.A.Q.

Disclaimer: The answers provided in this FAQ section are general in nature and should not be relied upon as formal legal advice. Each individual case is unique, and a separate analysis is required to address specific context and fact situations. For comprehensive guidance tailored to your situation, we welcome you to contact our expert team.

Confidential consultation

09000 00000

65 Queen Street west, Suite 1240, toronto, Ontario M5H 2M5

Requeast a Consulastion

our team of experienced lawyers are at your service