Executive Summary: Key Legal and Evidentiary Issues

• Characterisation of the Côte Saint-Luc drivers’ positions as “safety-related” and the extent of CPKC’s right to impose medical fitness requirements on existing employees.
• Reasonableness of the employer’s initial demand for comprehensive medical examinations and drug screening at an external clinic, versus less intrusive means of obtaining fitness-to-work information.
• Scope of the arbitrator’s continuing jurisdiction (functus officio) and whether the second award impermissibly revisited or contradicted conclusions in the first award.
• Alleged infringement of drivers’ fundamental rights and privacy through compulsory medical exams and detailed health questionnaires, including questions on alcohol and cannabis use.
• Assessment of serious or irreparable prejudice to employees if they must comply with the questionnaire pending judicial review, versus the employer’s claimed safety risks.
• Application of the tripartite test for a stay of an administrative decision (appearance of right, serious prejudice, balance of convenience) in the context of labour arbitration awards.

Factual background

Canadien Pacifique Kansas City (CPKC) operates as a railway company. In January 2024, it notified drivers working in the closed automobile compound at Côte Saint-Luc (the “Chauffeurs”) that their positions would henceforth be designated as “safety-related positions” (“poste lié à la sécurité”). This change affected 31 existing employees already in the Chauffeur role at that time. Their tasks mainly involve loading and unloading vehicles on train wagons inside a closed automotive yard, including heavy handling and work around moving rail equipment. CPKC’s safety rationale was that such work carries risks of accidents for both the drivers and others working in the facility.

Following the new designation, CPKC announced that in order to confirm the drivers’ fitness to occupy a safety-related position, they would be required to undergo medical examinations at an external clinic chosen by the employer. The medical protocol included a drug-screening test. This demand was directed specifically at employees already in the Chauffeur position, and did not concern future hires or later reassignments to the job.

First arbitration: dispute over safety-related designation and medical exams

The union, Section locale TC 1976 du Syndicat des Métallos, filed two grievances. First, it challenged the classification of the Chauffeurs as occupying a “safety-related” position. Second, it contested the decision to impose a compulsory medical exam, including drug testing, on employees who were already in that role. The grievances proceeded to arbitration under the Canada Labour Code.

In a first award issued in November 2024, the arbitrator Graham J. Clarke made several key determinations. On the classification issue, he held that CPKC acted reasonably in designating the Chauffeur position as “safety-related,” recognizing the legitimate safety concerns in the railway context. He also affirmed, in general terms, that an employer may request medical information from employees in certain circumstances to ensure fitness for work, particularly where safety is implicated.

However, he concluded that CPKC’s specific demand—requiring all Chauffeurs to undergo a medical exam, including drug screening, at an outside clinic selected by the employer—did not meet the standards established in the case law. The demand was viewed as overbroad and not justified in respect of this particular group of existing employees, who were already in the role and whose tasks had not changed with the new designation. The arbitrator analyzed the Railway Safety Act and the Railway Medical Rules and noted that they did not themselves authorize the employer to impose such exams on these “safety-related” positions; any such right had to be grounded in jurisprudence and collective labour principles. On that basis, he found the employer’s blanket requirement for exams and drug tests unreasonable for the 31 incumbents.

Importantly, the arbitrator did not deny that CPKC could ever seek medical information from these drivers. He left it to the parties to agree on what mandatory medical information could reasonably be required, and, failing agreement, indicated that CPKC could make a further, more tailored request for certain medical information, provided its validity could be justified. He also formally remained seized of issues linked to the matters examined in the first award, meaning he kept jurisdiction to deal with related questions that had not yet been fully resolved.

Second arbitration: medical questionnaire and functus officio challenge

After the first award, CPKC modified its approach. Instead of insisting on exams in a single external clinic with drug testing, it asked the Chauffeurs to complete a medical questionnaire and undergo a medical exam that could be performed at a clinic of their choice. The revised scheme removed the obligation to submit to drug-screening tests. Instead, the questionnaire contained a series of health questions, including a section on alcohol and cannabis consumption, and required an examining health professional to perform certain assessments (hearing test, visual acuity test, physical examination) and to comment on affirmative responses relating to particular health problems.

The union and the employer could not agree on the acceptability of this questionnaire. CPKC therefore returned to the arbitrator, seeking a ruling. The union raised preliminary objections, arguing that the arbitrator was functus officio—that is, he had exhausted his jurisdiction with the first award and could not revisit the medical-exam issue—and, alternatively, that no grievance specifically targeting this new questionnaire had ever been referred to him.

In a second award rendered in November 2025, the arbitrator rejected the union’s preliminary objections. He reasoned that he had remained seized of the dispute, and that the questionnaire was essentially part of the original medical-exam controversy. In his view, the first award had not completely disposed of all aspects of the medical-information issue. He therefore held that he was not functus officio and retained authority to address CPKC’s revised request. On the merits, he concluded that CPKC could require the Chauffeurs to complete the medical questionnaire, except for the sections dealing with their consumption of alcohol and cannabis, which he found impermissible.

Judicial review and motion for a stay before the Superior Court

The union brought an application for judicial review in the Superior Court of Québec to challenge the second arbitral award, and, at the same time, applied for a stay (sursis) of its execution pending a decision on the merits of the review. The stay application is the subject of the Superior Court judgment.

In addressing the first stay criterion, appearance of right, the Court had to be satisfied that the judicial review grounds were not frivolous, and that there were at least arguable weaknesses in the arbitrator’s reasoning. CPKC argued that the review was late because it was served 33 days after the second award and that, under the Code of Civil Procedure, judicial review must be instituted within a “reasonable” time, presumptively about 30 days for this type of decision. The Court held that this alleged lateness did not, by itself, negate any appearance of right: the union remained entitled to show that, in the circumstances, the delay was still reasonable, a question to be decided on the merits by the judge hearing the review.

Turning to the substance, the union contended that the applicable standard of review was reasonableness, consistent with the Supreme Court’s presumptive framework in Canada (Minister of Citizenship and Immigration) v. Vavilov. It argued that the arbitrator’s conclusion that he was not functus officio was unreasonable because he blurred the line between “medical information” and a full “medical examination.” According to the union, under the first award the arbitrator had effectively determined that CPKC could not require these 31 existing Chauffeurs to undergo medical examinations following the change in designation, and the questionnaire, as designed, still obliged them to submit to exams and physical testing. By authorizing CPKC to compel completion of that questionnaire (subject only to removing the alcohol/cannabis-use sections), the union said the arbitrator had contradicted or overturned portions of his own earlier decision.

The Court reviewed key passages from the first award showing the arbitrator’s detailed analysis of “examinations” and “tests” and his conclusion that CPKC’s original demand for mandatory exams and drug testing for all existing Chauffeurs was unreasonable, particularly given that they were already in the job and that the tasks had not changed with the “safety-related” label. It held that, at least on a preliminary view, there was a serious question as to whether the arbitrator had reasonably found that he was not functus officio and whether the second award effectively reversed or undermined essential conclusions of the first. Since a single serious issue suffices to meet the “appearance of right” threshold, the Court considered that criterion satisfied and did not need to address the union’s other review grounds at the stay stage.

Serious or irreparable prejudice and balance of convenience

On the second criterion, serious or irreparable prejudice, the Court focused on the practical consequences for the Chauffeurs if the stay were refused. They had refused to comply with the questionnaire, asserting that it infringed their fundamental rights, particularly privacy and bodily integrity. If the stay were denied and they still refused, they faced significant sanctions, including removal from service, with potentially serious impacts on their employment income. This was characterized as a serious prejudice.

Conversely, if they complied with the questionnaire pending judicial review, they would be doing precisely what they sought to prevent by bringing the review, thereby potentially rendering the proceeding academic. The Court considered that, assuming for the purposes of the stay analysis that the employees might ultimately succeed on the merits, being forced to undergo the questionnaire and associated exams would amount to an infringement of fundamental rights that would be difficult to adequately remedy afterward, supporting a finding of serious or irreparable harm.

For the third criterion, balance of convenience (preponderance of inconveniences), the Court weighed the drivers’ potential harm against CPKC’s asserted need to promptly verify their medical fitness for safety reasons. While recognizing that the employer’s preventive safety concerns were legitimate in principle, the Court noted that the 31 Chauffeurs had long been in their positions, that their tasks did not change when the job was reclassified as “safety-related,” and that the position did not present the same level of risk as a “safety-critical” job. The two accidents invoked by CPKC—one allegedly involving driving under the influence in the Côte Saint-Luc yard, and another involving a fall from a similar railcar ladder in Kansas—were found insufficiently linked or documented to establish a concrete, heightened risk specific to this group of employees during the relatively short period until the judicial review would be decided.

On that record, the Court held that the prejudice to the Chauffeurs if the stay were refused clearly outweighed any inconvenience to CPKC of waiting for the outcome of the judicial review before enforcing the questionnaire.

Outcome and financial consequences

In light of its analysis, the Superior Court granted the union’s application for a stay. It ordered a suspension of the execution of the second arbitral award (decision AH881-S of 7 November 2025) until judgment is rendered on the merits of the union’s judicial review, and it awarded legal costs (“frais de justice”) in favour of the union. The successful party in this Superior Court decision is therefore Section locale TC 1976 du Syndicat des Métallos, which obtained a stay preventing CPKC from enforcing the medical questionnaire against the 31 Chauffeurs while the lawfulness of the second arbitral award is scrutinized. The judgment does not specify any exact amount for damages, compensation or costs, so the total monetary award or costs ordered in the union’s favour cannot be determined from this decision.