Part I (Industrial Relations) of the Canada Labour Code (the Code) governs workplace relations and collective bargaining between unions and employers. This part contains provisions related to replacement workers and maintenance of activities, as well as dispute resolution, strikes and lockouts. It outlines the labour relations rights and responsibilities of employers, trade unions and employees.
On June 20, 2025, amendments to Part I of the Code and the Canada Industrial Relations Board Regulations, 2012, that were proposed through Bill C-58, An Act to amend the Canada Labour Code and the Canada Industrial Relations Board Regulations, 2012, which received royal assent on June 20, 2024, came into effect. This legislation has two main components.
First, it repealed the previous limited prohibition on replacement workers and replaced it with the following:
- Employers are banned from using several types of people to do the work of striking or locked out workers. This includes any employee or manager hired after the employer or union gives notice to bargain.
- For employees hired before notice to bargain, employers can only use employees if they normally worked at the location where the strike or lockout is taking place before notice to bargain is given.
- Employers are also prohibited from using contractors to fill in and do union work during a strike or lockout, regardless of when they were hired.
- Employers cannot use volunteers, students or members of the public to fill in and do union work during a strike or lockout.
- In addition, employers are prohibited from allowing employees in a bargaining unit to "cross the picket line" and work, if the bargaining unit is involved in a full strike or lockout where all employees are expected to stop working.
- Employers are allowed to use replacement workers in exceptional circumstances to prevent threats to life, health or safety of the public; to prevent destruction or serious damage to the employer's property or premises; or to prevent serious environmental damage affecting the employer's property or premises. In these circumstances, employers are required to offer bargaining unit members the opportunity to do the necessary work before using replacement workers.
- A violation of the replacement worker prohibition is considered an unfair labour practice under Part I of the Code. If a union or an employee believes an employer is illegally using these workers, they can file a complaint with the Canada Industrial Relations Board (CIRB).
- The CIRB will investigate complaints and, if necessary, will order the employer to stop. Violating the prohibitions can be made an offence, and, if prosecuted and convicted, an employer can be subject to a fine of up to $100,000 per day.
Second, it amended the maintenance of activities process as follows:
- Employers and unions are required to enter into an agreement no later than 15 days after notice to bargain has been given and are required to immediately file their agreement with the CIRB and the Minister of Jobs and Families. This condition applies even if the parties agree that no activities need to be maintained.
- If the parties do not come to an agreement within 15 days after the notice to bargain has been given, they are required to apply to the CIRB to decide which activities need to be maintained, if any.
- The CIRB is required to resolve these matters within 82 days and is empowered to expedite proceedings. The Minister continues to have the authority to refer questions to the CIRB about whether an agreement is sufficient to prevent an immediate and serious danger to the safety or health of the public.
- Employers and unions are required to have a maintenance of activities agreement in place before they can issue 72 hours' notice for a strike or lockout.
