Canada’s largest union is accusing the Toronto Transit Commission (TTC) of using a technical objection to halt operation supervisors from joining a union.

The Canadian Union of Public Employees (CUPE) says almost 90 per cent of the supervisors, who oversee TTC bus and street car operators, voted on Thursday to unionize.

However, they claim the TTC is blocking the votes from being counted, calling it “a delaying tactic by the employer,” in a statement.

The TTC has responded to the claim, saying while they respect the rights of their employees to participate in the representation vote, it’s against the law for supervisors to unionize as they are “an employer’s first line of management.”

In a statement, TTC spokesman Stuart Green added it has consistently been the finding of the Ontario Labour Relations Board (OLRB) when supervisors have attempted to unionize.

“As is standard in these situations, when the OLRB ordered the vote, it also directed the ballot box be sealed while the matter is being resolved,” read the statement from Green.

CUPE says the operation supervisors decided to unionize over concerns about health and safety, workload, constant schedule tampering and forced overtime.

“These are people who work around the clock, 24/7, to ensure smooth operation of the TTC in the event of accidents or emergencies, and they deserve better treatment from their employer,” read CUPE’s statement.