Interlocutory Injunctions in Ontario: Stopping Harm Before Trial

A lawsuit can take a long time to reach trial — and sometimes waiting that long means real, irreversible damage is done before a judge ever hears the full case. That's what an interlocutory injunction is designed to address in Ontario: a temporary court order that stops (or sometimes requires) specific conduct while the underlying lawsuit is still working its way through the system.

Injunctions are powerful, which is exactly why Ontario courts don't hand them out easily. Understanding the test and the practical process helps you assess, realistically, whether one is worth pursuing.

What an Interlocutory Injunction Does

An interlocutory injunction is a temporary order made before trial, lasting until trial or further order of the court. It's typically sought when a party believes that without immediate intervention, they'll suffer harm that can't be fixed later — even if they eventually win the underlying lawsuit.

Common scenarios where parties seek one include disputes involving:

• A business relationship where one side is about to take an action that would cause lasting damage (e.g., misusing confidential information)
• Property disputes where conduct on the property could cause damage that's hard to reverse
• Situations involving restrictive covenants or non-competition disputes
• Circumstances where a delay until trial would effectively make the lawsuit pointless

The General Test Courts Apply

Ontario courts apply a demanding, multi-part test before granting an interlocutory injunction. In general terms, a party asking for one typically needs to show:

• A serious issue to be tried — the underlying claim has real merit, not necessarily that it will definitely succeed, but that it's not frivolous or bound to fail.
• Irreparable harm — without the injunction, the requesting party will suffer harm that can't adequately be fixed later with money damages.
• Balance of convenience — weighing the harm to the requesting party if the injunction is refused against the harm to the other side if it's granted, the balance favours granting it.

This is described here only as general, well-established common-law background — courts apply this kind of multi-part analysis, but the exact weighing is always fact-specific and left to the court's discretion in each case.

Why Injunctions Are Hard to Get

Courts are cautious about interlocutory injunctions because they effectively decide part of the outcome before the case has been fully heard. A few reasons they're difficult in practice:

• The irreparable harm requirement is strict — if the harm can realistically be compensated with money later, courts are reluctant to intervene early.
• Evidence has to be strong at an early stage — you're asking a court to act before the normal discovery and trial process has unfolded.
• The requesting party usually has to give an undertaking as to damages — a promise to compensate the other side if it turns out the injunction shouldn't have been granted.
• Urgency cuts both ways — genuinely urgent situations can support an injunction, but a party who waited too long to ask for one may find that delay undermines the claim of urgency.

The Practical Process

Seeking an interlocutory injunction generally involves:

1. Assessing whether the situation genuinely meets the test — a lawyer evaluates whether the harm is truly irreparable and whether the underlying claim is strong enough to support the request.
2. Preparing evidence quickly, usually by affidavit — because injunction motions often move fast, the evidentiary record has to be assembled promptly and carefully.
3. Bringing the motion before the court, sometimes on an urgent or expedited basis if immediate harm is threatened.
4. Offering an undertaking as to damages, since courts generally expect this before granting relief that affects the other side before trial.
5. Living with the order until trial or further order, meaning ongoing compliance obligations for both sides while the underlying case proceeds.

In genuinely urgent situations, a party may seek relief without formally notifying the other side first, though this is reserved for real emergencies and generally comes with tight follow-up requirements to give the other side a chance to respond quickly afterward.

Alternatives to Consider First

Because interlocutory injunctions are hard to obtain and can be costly if unsuccessful, it's worth considering whether other tools address the same problem:

• A demand letter or cease-and-desist correspondence, which sometimes resolves the issue without court involvement at all
• Negotiation or mediation, particularly where an ongoing relationship makes a fast, cooperative resolution more valuable than a court fight
• Proceeding straight to trial on an expedited basis, in situations where the harm, while serious, isn't quite at the level courts treat as irreparable

A lawyer can help assess honestly whether an injunction is the right tool, or whether it's likely to fail the test and simply add cost and delay.

Frequently asked questions