The appellants, Dairy Farmers of Ontario and Dairy Farmers of Canada, appealed a Master's order dismissing their motion to intervene as added parties in an application challenging the constitutionality of mandatory milk pasteurization laws.
The Master had dismissed the motion based on the Supreme Court's decision in Northwestern, finding that allowing the appellants to intervene would violate their impartiality as administrative bodies.
The Divisional Court allowed the appeal, holding that the Master erred in applying Northwestern, as the underlying application was a constitutional challenge to a statute, not a judicial review of the appellants' own decisions.
The Court found the appellants met the criteria under Rule 13.01 and could make a useful contribution given their specialized expertise.