The union that represents 23,000 inside workers will hold a strike vote on Tuesday.
"We did not come by the decision to seek a strike mandate lightly," said Tim Maguire, local 79 president in a statement released Sunday.
"Our goal is to negotiate fair collective agreements without a strike. It's now clear the city can't say the same without something to focus their attention."
CUPE Local 79 represents the civil servants, social service employees, ambulance dispatchers, janitors, public health nurses, childcare workers and court service staff, among others.
Their collective agreement expired Dec. 31, 2011.
Maguire said the city has not budged in regards to a list of major concessions affecting full- and part-time employees, even adding more concessions after requesting a no board.
"We are not holding a vote because we want to stop working," said Maguire. "We are doing it because we want the city to start talking."
Local 79 has also scheduled a ratification vote in case a deal is reached.
"That’s our target, and that should also be the city’s focus," he said.