The stakes of an interlocutory injunction
When your opponent moves for an interlocutory injunction, they are asking the court to impose immediate and extraordinary relief before trial. These orders can disrupt business operations, freeze rights or assets, and shift the strategic balance of the litigation.
Responding effectively — and quickly — is essential.
This guide explains the governing legal test, common weaknesses in the moving party’s evidence, and strategic defences that can be used to defeat a motion for interlocutory injunctive relief in Ontario.
Understanding the legal framework: what the moving party must show
Interlocutory injunctions are discretionary equitable remedies. The Supreme Court of Canada established the modern test in RJR-MacDonald Inc. v. Canada (Attorney General), 1994 CanLII 117 (SCC):
- A serious question to be tried.
- Irreparable harm if the injunction is not granted.
- Balance of convenience favouring the injunction.
Courts in Ontario apply this test consistently.
Mandatory injunctions require a higher threshold
Where the relief sought is mandatory — compelling a party to take a positive step rather than refrain from acting — the moving party must establish a strong prima facie case, not merely a serious question to be tried. See:
- v. Canadian Broadcasting Corp., 2018 SCC 5
- Google Inc. v. Equustek Solutions Inc., 2017 SCC 34
- BMW Canada Inc. v. Autoport Limited, 2022 ONCA 725
This higher threshold is often fatal to a weak or speculative motion.
Common weak points in the moving party’s case
These vulnerabilities frequently arise and provide strong grounds for opposing an injunction.
1. Failure to establish a strong prima facie case
If the facts are disputed, the evidence is inconsistent, or key legal elements are missing, the moving party cannot meet even the basic RJR-MacDonald threshold — let alone the heightened standard for a mandatory injunction.
Ontario courts repeatedly deny injunctions on this basis alone:
- Hanna v. Ontario (Attorney General), 2023 ONSC 4822
- Ontario (Attorney General) v. Weyer, 2021 ONSC 7053
2. Lack of irreparable harm
“Irreparable” means harm not compensable by damages. This is a high bar.
Economic loss is usually quantifiable and therefore not irreparable.
Key authorities:
- Potash Corp. of Saskatchewan Inc. v. Mosaic Canada ULC, 2011 SKCA 120
- Amplify Energy Corp. v. Electrify Oil Sands Inc., 2023 ABCA 51
If the harm can be calculated, mitigated, or reversed after trial, the injunction fails.
3. Balance of convenience favours the respondent
Courts weigh the degree of harm to both sides. If granting the injunction would cause significant disruption, cost, reputational damage, or operational impact to the respondent, courts often refuse the relief.
Leading cases:
- RJR-MacDonald Inc. v. Canada (Attorney General), 1994 CanLII 117 (SCC)
- Morguard Corp. v. De Savoye, 1990 CanLII 29 (SCC) (balance of equities principles)
4. Delay, acquiescence, and equitable bars
Because injunctions are equitable, a plaintiff’s own conduct can defeat their request.
Ontario courts have dismissed injunction motions for:
- Delay: Brown v. University of Windsor, 2012 ONSC 284
- Acquiescence or clean-hands issues: Robertson v. Thomson Corp., 2006 SCC 43
- Failure to act with urgency: Irving Shipbuilding Inc. v. Canada (Attorney General), 2009 FCA 116
If the plaintiff slept on their rights, knowingly allowed the conduct to continue, or is themselves engaged in improper conduct, the injunction should be dismissed.
Strategic practical steps to mount your defence
◾ Secure evidence immediately
Affidavit evidence, correspondence, timelines, and operational documents must be gathered quickly to rebut the moving party’s narrative.
◾ Characterize the relief properly
If the order sought is in substance mandatory, emphasize the higher “strong prima facie case” requirement (CBC, 2018 SCC 5).
◾ Quantify harm
Show that any alleged injury is compensable with damages — defeating RJR-MacDonald’s irreparable harm branch.
◾ Demonstrate disproportionate prejudice
Provide evidence of actual financial, operational, or reputational harm your client would suffer if the injunction is granted.
◾ Establish the equities
Use delay, acquiescence, or contradictory conduct to invoke equitable discretion against granting the injunction.
◾ Propose alternatives
Where appropriate, propose narrower interim measures — showing reasonableness and undermining the alleged urgency.
Why this matters for high-stakes civil litigation
Interlocutory injunctions can create immediate, far-reaching consequences in commercial, corporate, real estate, employment, and partnership disputes.
Ontario courts emphasize that injunctions are exceptional and should not be granted lightly. The jurisprudence consistently reinforces that failure to meet any branch of the RJR-MacDonald test is fatal.
Statutory framework:
- Courts of Justice Act, R.S.O. 1990, c. C.43, ss. 101, 106 (injunctive jurisdiction)
- Rules of Civil Procedure, R.R.O. 1990, Reg. 194, Rule 40 (injunctions and receiverships)
A well-crafted responding record can stop an injunction in its tracks — often turning the momentum of the entire case.
Conclusion: A clear message to respondents — act decisively
If your opponent has served a motion for an interlocutory injunction, the law gives you powerful tools to defeat it. The outcome is often determined not by urgency but by evidence, narrative, and the equities.
At ME Law, we guide clients through these high-pressure moments with the strategic precision required to neutralize improper or overreaching injunction motions and protect your interests.
Want to know more? Explore our related articles:
- How Judges Think — unpacking judicial reasoning and decision-making.
- How Factums Should Be Written — best practices for drafting persuasive motion and trial materials.
Contact ME Law
If you are facing a high-stakes commercial, real estate, estate, or corporate dispute — or you need decisive trial counsel who can take your matter from strategy to courtroom execution — ME Law is here to help.
ME Law Professional Corporation
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⬛⬜🟥 Disclaimer: This article is for general informational purposes only and does not constitute legal advice. Every case is unique. If you face a motion for an interlocutory injunction, you should consult a qualified litigation lawyer promptly.