A Just-Cause Analysis Framework for Canadian Labour Arbitration

The standard multi-step framework Canadian arbitrators apply when deciding whether an employer had just cause to discipline or discharge a unionised employee.

The four-part just-cause test

When a union challenges discipline or discharge in a Canadian unionised workplace, the arbitrator does not ask a single yes-or- no question. They work through a structured four-part framework that has become the standard in Canadian labour arbitration. The framework is most fully articulated in Canadian Labour Arbitration(Brown & Beatty), the reference text Canadian arbitrators cite. The four parts are typically framed as follows:

  • (1) Did the employee engage in conduct warranting discipline? The arbitrator first decides, on a balance of probabilities, whether the alleged misconduct actually occurred. The employer bears the burden of proving the facts.
  • (2) Was the discipline imposed proportionate to the misconduct? Even where the misconduct is proven, the arbitrator asks whether the penalty matches the seriousness of the conduct, considering aggravating and mitigating factors, the employee's record, and whether progressive discipline was followed.
  • (3) Was procedural fairness observed? Did the employer follow its own disciplinary process, give the employee notice of the allegations, allow an opportunity to respond, and conduct a fair investigation? Procedural defects rarely invalidate discipline on their own, but they can influence the outcome.
  • (4) Are there mitigating factors that justify reducing the penalty? Length of service, disciplinary record, remorse, rehabilitation, personal circumstances, and the employer's own conduct can all reduce the sanction the arbitrator ultimately upholds.

Progressive discipline and the culminating incident doctrine

Canadian arbitrators apply a preference for progressive discipline — the idea that an employee should be given a chance to correct their behaviour through escalating steps (counselling, verbal warning, written warning, suspension, discharge) before the ultimate sanction is imposed. A discharge for a first offence is rarely upheld unless the conduct is egregious.

The culminating incident doctrine is how arbitrators reconcile progressive discipline with real-world cases where the final incident, considered in isolation, might not justify discharge. Under the doctrine, the arbitrator can consider the employee's full disciplinary record alongside the final incident. If the pattern as a whole demonstrates that the employee has failed to respond to progressive discipline, the discharge can be sustained even if the final act is relatively minor. The employer must have clean hands — the prior discipline must itself have been appropriate and properly communicated.

The McKinley standard for summary dismissal

In non-unionised contexts, the Supreme Court of Canada's decision in McKinley v BC Tel established that summary dismissal for dishonesty requires a contextual analysis — the dishonesty must be serious enough to be fundamentally inconsistent with the employee's obligations and to give rise to a breakdown in the employment relationship. While McKinley is a common law wrongful dismissal case, its reasoning has influenced how labour arbitrators approach allegations of dishonesty in the unionised context. Arbitrators look at the nature and degree of the dishonesty, the circumstances surrounding it, and the nature of the work. A single instance of minor dishonesty is unlikely to justify discharge; sustained, deliberate dishonesty that undermines the employment relationship is a different matter.

How Sertus encodes the framework

Sertus encodes the just-cause framework into its scenario checker and case assessment features. When a discipline or discharge case is loaded into the platform, Sertus walks through the four-part test, flags the facts relevant to each step, and surfaces the most comparable arbitral decisions. The output is not an arbitrator's ruling — it is a structured preparation tool that helps the business agent, steward, or labour relations officer see the case the way an arbitrator will.

Sertus is built by the co-author of Canadian Labour Arbitration(Brown & Beatty), so the framework in the platform is the same framework used by the arbitrators who will hear the case. This article is general information, not legal advice — consult counsel for any specific matter.

Next steps

If you want to see the just-cause framework applied to a real case inside Sertus, book a demo. See also our pages on the scenario checker, arbitration decisions research, and grievance management.

Last updated: April 2026

Assess discharge cases the way arbitrators do

A 30-minute demo showing Sertus apply the just-cause framework to a real discharge case, with comparable arbitral decisions in context.