The Union filed a policy grievance regarding the employer's use of non-bargaining unit agency personnel to perform bargaining unit work.
The arbitrator found that the arrangement constituted 'contracting in' rather than 'contracting out', and that the collective agreement contained an implied term prohibiting the use of agency workers in this manner for longer than two weeks.
The Divisional Court set aside the award on judicial review, finding it patently unreasonable.
The Court of Appeal allowed the Union's appeal, holding that the arbitrator did not exceed his jurisdiction and that his interpretation of the collective agreement was not patently unreasonable.