But CUPE Local 79 president Tim Maguire told a news conference today no walkout is being planned for now.
He would not say now may people voted because it's "an internal matter," adding only the workers voted in "historic numbers."
Maguire says while the union wants to get a deal at the table, the union will take action if the city tries to act unilaterally to impose terms and conditions that would withdraw fundamental rights from workers.
He said the union would provide sufficient notice in the event of a strike.
The 23,000 inside workers include child-care workers, ambulance dispatchers, nurses, janitors and parks and recreation staff. They can strike or be legally locked out on Saturday, which means daycares, most recreation centres and city-run swimming pools would be closed.
Maguire said the strong strike mandate will assist the union in reaching a fair settlement, as well as uphold basic employment protections for the workers.
The union has accused the city of bargaining in bad faith and filed a complaint with the Ontario Labour Relations Board.
But the city says the union has been unavailable for negotiating for seven of the last 17 days.