Common mistake regarding COLA calculation does not vitiate a ratified collective agreement.
The Minister of Labour referred a question to the Ontario Labour Relations Board pursuant to section 107 of the Labour Relations Act regarding his authority to appoint a conciliation officer.
The employer and the trade union had signed a memorandum of agreement, but the union argued it was null and void due to a common mistake regarding the calculation of a cost of living allowance (COLA) fold-in.
Both parties had mistakenly assumed the COLA entitlement was 10 cents per hour instead of 21 cents.
The Board held that the doctrine of common mistake does not vitiate a collective agreement where the parties specifically directed their minds to stipulated amounts and agreed to them without fraud or misrepresentation.
The Board concluded that a binding collective agreement was in effect and the Minister had no authority to appoint a conciliation officer.
PPG Industries Canada Ltd. London Merchandizing Branch v. Energy and Chemical Workers Union, 1986 CanLII 1543