Supreme Court Of Canada Clarifies The Role Of Interveners

• Published date: 23 November 2021
• Subject Matter: Litigation, Mediation & Arbitration, Trials & Appeals & Compensation
• Law Firm: McCarthy Tétrault LLP
• Author: Canadian Appeals Monitor, Adam Goldenberg, Connor Bildfell and Jesse Hartery

An intervention is a procedural device that allows a non-party to participate in a proceeding.¹ At the Supreme Court of Canada, interventions have become routine. For example, between 2015 and 2018, about two thirds of Supreme Court proceedings featured at least one intervener, and an average of 252 interveners - including corporations, trade associations, non-profits, and individuals - appeared before the Court each year.² These statistics reflect the integral role interveners play in Supreme Court cases, which often have broader impacts beyond the parties to the dispute. Below, we summarize the intervention process, the Supreme Court's recent guidance on the role of interveners, three practical intervention tips, and how we can help.

What is an intervention?

The Rules of the Supreme Court of Canada³ (the "Rules") govern the Supreme Court intervention process. Under the Rules, any person interested in an application for leave to appeal, an appeal, or a reference to the Supreme Court may apply for intervener status.⁴ In the case of an appeal, the proposed intervener must bring its application within four weeks after the appellant has filed its factum.⁵ This application must set out the proposed intervener's relevant expertise or experience, its interest in the proceeding, and its proposed submissions.⁶

The Supreme Court enjoys a wide discretion in deciding whether, and on what terms, to allow a proposed intervention.⁷ At a minimum, however, the applicant must show that it: (1) has an interest in the proceeding; and (2) will make submissions that are both useful and different from the parties' submissions.⁸ To illustrate, an applicant may meet the first criterion by showing that it "represent[s] an interest which is directly affected by the appeal",⁹ and may meet the second criterion by showing that it has "a history of involvement in the issue giving the applicant an expertise which can shed fresh light or provide new information on the matter".¹⁰

Since the Charter's enactment in 1982, the Supreme Court has granted intervener status increasingly liberally.¹¹ In a typical year, the Supreme Court grants over 90% of intervention motions.¹² In deciding whether to allow an intervention, the Supreme Court must weigh the goal of preserving scarce judicial resources against the goal of permitting interested individuals and groups to be engaged in the judicial process, and the value to the Court of that engagement.

If the Court grants an intervention, it may set...