TORONTO -- Ontario's education workers will head back to the bargaining table this weekend amid preparations for a work-to-rule campaign starting Monday.

The Canadian Union of Public Employees said in a statement Wednesday that talks with the province are set to take place Saturday and Sunday.

The news comes the same day the union issued the required five days' notice to put it in a legal strike position.

The head of the bargaining unit for the 55,000 custodians, clerical workers and early childhood educators said members are resolved to start their work-to-rule if cuts by the provincial government aren't reversed.

"If it takes job action to restore these services, then so be it," Laura Walton said in the statement.

Contracts for Ontario's public school teachers and education workers expired Aug. 31, and the major unions are in various stages of bargaining. The talks are happening as the government has ordered school boards to start increasing class sizes, moving to an average of 28 for high schools over four years, up from 22. Class sizes for grades 4 to 8 will increase from 23 to 24.

The government has said that will mean 3,475 fewer teachers in the system over four years, a cut it says will be accomplished by not filling vacancies when teachers quit or retire.

Under CUPE's planned work-to-rule action, union members would stop working overtime and performing any extra duties.

Education Minister Stephen Lecce said the government is returning to talks and remains optimistic an agreement can be reached with the union.

"Parents of the province need to hear this directly from me," he said. "I want to land a deal and I want to do so at the table so that their kids can remain in class."

Lecce added that the safety of children should not be compromised during any potential work-to-rule action.

"My hope, in my heart of hearts, is that every member of the unions and all of our bargaining partners will always make sure the safety of our students remains paramount," he said.

The union issued a series of job action instructions to the workers Wednesday detailing duties they should and should not complete.

Custodians are not to clean hallways, office areas or gymnasiums, cut school lawns or pick up or empty garbage cans outside of schools.

Clerical workers are not to replace paper or perform photocopier repairs, find replacements for absent staff or administer any medications.

Education assistants are not to prepare materials for any class, complete student attendance or allow class to start without a teacher present, and information technology staff are not to perform repairs of any kind.

And library workers are not to supervise students during lunch clubs or on yard duty, participate in book fairs or complete paperwork of any kind including issuing overdue notices.

This report by The Canadian Press was first published Sept. 25, 2019.