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Complaint concerning a prohibited practice

Workers may file a complaint if they believe they are the victim of sanctions, discriminatory measures or reprisals prohibited by law on the part of their employer.

Recognizing a prohibited practice

In certain circumstances, an employer is prohibited from imposing a sanction on a worker. For example, a worker may not be dismissed, suspended, transferred or have any other sanction imposed on them if they:

Example 1

Jacynthe just found out she is pregnant. She tells her employer the good news and discusses her maternity leave with them. A few days later, she finds out she has been dismissed. Jacynthe could file a complaint concerning a prohibited practice. An employer may not dismiss a worker because she is pregnant.

Example 2

François has to take time off work because his child's daycare is closed due to a plumbing problem. His employer threatens to dismiss him. If dismissed, François could file a complaint concerning a prohibited practice. An employer may not dismiss a worker who is absent from work to fulfil family or parental obligations.

Section 122 of the Loi sur les normes du travail provides for several other grounds for the various prohibited practices.

If a worker is dismissed or disciplined for a reason prohibited by the Act, it will be up to the employer to prove that they did not do so.

How the complaints process works

Filing a complaint

There are 2 ways for a worker to file a labour standards complaint:

There are several steps in the complaints process. Throughout the process, the worker is asked to cooperate with various CNESST officers, in particular by providing the information and documents requested.


The worker has 45 days to file a complaint from the day of their dismissal or the sanction. In the case of a worker who is forced to retire, or who has a sanction imposed on them after refusing to retire, the time limit is 90 days.

Analysis of the complaint

Once the complaint is filed, a member of the CNESST contacts the worker to verify whether the complaint is admissible. Among other things, they make sure that: 

  • the grounds for the complaint are provided for in the Loi sur les normes du travail (LNT)
  • the worker is an employee within the meaning of the LNT
  • their employer is subject to the LNT 
  • the person has no other recourses under a collective agreement or other act 
  • the complaint was filed within the time limit prescribed by the LNT

If the CNESST can follow up on the complaint, it notifies the worker and checks whether the disagreement can be resolved by communicating with the employer, for example, to explain the standards that apply. If this is not possible, a number of options are provided for to try to resolve the situation.

If the CNESST considers that it cannot follow up on the complaint, it notifies the worker and explains why. If the person disagrees with the decision, they have 30 days to contest it by completing the Request for review of the decision form. The CNESST has 30 days to respond.


When a complaint is filed, the CNESST offers a free mediation service to the worker and their employer. They are free to accept or refuse mediation.

If mediation is refused or if an agreement cannot be reached, other options are proposed to try to resolve the situation.

Transfer of the file to the CNESST’s legal affairs department


A complaint concerning a prohibited practice is heard by the Tribunal administratif du travail. If the judge determines that the complaint is founded, they may order the employer to:

  • reinstate the worker in their job with all their rights and privileges
  • pay the worker an indemnity equivalent to the amount of wages and benefits lost as a result of the sanction

In the case of a domestic or a babysitter or care provider, the Tribunal administratif du travail judge may only order the employer to pay them an indemnity for the wages and other benefits they did not receive as a result of their dismissal.

Laws and regulations

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