STM: Another union announces strike

A passenger boards an STM bus on Nov, 14, 2025. (Christopher Katsarov/The Canadian Press)

Another strike is looming at the Société de transport de Montréal (STM), this time by a union that had not yet walked off the job — the one representing 800 professional employees.

The union plans to launch an overtime strike from December 17 to January 11.

In November, its members approved a mandate for 10 strike days to be used when deemed appropriate. At the time, vice-president Benoît Tessier noted it would be the union’s first strike in its 31-year history.

Members of this union are subject to essential-services requirements. Discussions will therefore be needed with the employer, and the Administrative Labour Tribunal will be called on to determine whether the essential-services list is adequate.

STM management said that “even though discussions between the parties must still take place to set the essential services that will be maintained, no impact on service delivery is expected.”

The union isn’t ruling out ramping up pressure in January. “The overtime strike is only the first step. We will evaluate our other options in January, knowing our members gave us a strong mandate. Nothing prevents us from increasing the pressure if STM management remains as inflexible at the start of 2026,” Tessier said.

The union represents professionals such as engineers, architects, analysts and advisers. It is a local of the Syndicat des employé(e)s professionnel(le)s et de bureau (SEPB), which is affiliated with the FTQ.

Roughly 30 meetings have been held between the STM and the union. The parties have been in mediation since October.

“The negotiations are continuing in mediation. As with the other union units, the STM is fully committed to reaching an agreement to avoid this strike,” management said.

The union says internal expertise and job security are key issues.

“For our members, it’s a fundamental breach of trust with management. The employer wants the option to show professionals the door at will, without justification and without limits. That’s unacceptable,” Tessier said.

For its part, management says “the STM wants to review the parameters of employee relocation, including reassignment timelines, to ensure the right resources are mobilized at the right time and to optimize internal expertise. Many projects are funded and time-limited. Job-security rules must reflect that reality to be realistic and viable in the current financial context.”

This strike would overlap partly with the one planned by 2,400 STM maintenance employees, who are set to walk off the job from December 11 to January 11. They also plan to refuse overtime. The Administrative Labour Tribunal is expected to issue its decision on essential services in their case in the coming days.

This report by The Canadian Press was first published in French on Dec. 5, 2025.