Who “owns” a grievance?
A collective agreement is a contract between the employer and all the workers in the bargaining unit. A grievance is usually defined as a violation of the collective agreement. For this reason, the union “owns” the grievance, not the individual grievor. This is what takes place with CUPE but is known to be different with other unions.
Unions do not have to submit a grievance just because a member asks them to. But by law unions must submit any grievance that has as reasonable chance of being successful. This is one part of what is called the Duty of Fair Representation. In addition, the union must also represent everyone in the bargaining unit.