CUPE Local 79 President Tim Maguire says a work-to-rule campaign that began Monday is aimed at making the public aware that union workers often perform duties outside of their regular job descriptions.

"Our workers often work for free and they're going to stop it," Maguire said in an interview on CBC's Metro Morning with host Matt Galloway. 

Maguire says the city's 20,000 inside workers represented by his union are engaging in a work-to-rule campaign, but they won't walk off the job.

He said they will continue to perform core duties, but none outside of their job descriptions. 

For example, a daycare worker or an employee of a recreation centre may decide not to shovel a snowy sidewalk or try to repair a malfunctioning photocopier. 

"They will still get paid, but they won't be working for free," Maguire said of union members. 

Local 79 is in talks with the city to reach a new contract. The last four-year deal expired on Dec. 31. 

Galloway asked Maguire if the work-to-rule campaign will escalate to a full-on strike if negotiations don't go well. Maguire didn't rule it out.

"We're going to be assessing our options as we go forward," he said. "The public understands if we're trying to protect components of a good job … they're supportive of us doing what we need to do."

Members of Local 79 work in community housing, community centres, arenas, child-care centres, public health offices, long-term care facilities and municipal offices, among other things. 

The city on Friday reached a tentative deal with CUPE Local 416, which represents outside workers. Mayor John Tory has said the city needs to reach a similar deal with Local 79.