A major union representing education workers in Ontario says its members have voted overwhelmingly in favour of a potential strike that could take effect by the end of the month.

The Canadian Union of Public Employees says 93 per cent of its 55,000 members voted in favour of job action, putting them in a legal strike position as of Sept. 30.

The union says that while it intends to continue bargaining with the Ontario government and hopes to avoid a strike, its members are concerned about recent changes to the province's education system.

The measures include increases to average class sizes, shifts towards online learning models and a gradual reduction in the number of working teachers.

The changes were implemented over the past year by the Progressive Conservatives under Premier Doug Ford.

The President of CUPE's bargaining unit says members are prepared to walk off the job in order to push back against what they see as cuts that will compromise the quality of education in Ontario's schools.

"Families, students, and workers have all been hurt by the Ford government's cuts to education," Laura Walton said in a statement. "Our plan for job action is about standing up for students and protecting the services that CUPE education workers deliver across the province."

CUPE had requested an item known as a "no-board report" earlier in the month, which essentially started the countdown towards a potential strike.

Walton had said workers would not walk out if progress was being made at the bargaining table, and said the union still planned to proceed with negotiations scheduled for Sept. 17 and 18.

Contracts for Ontario's public school teachers and education workers expired Aug. 31, and the major unions are in various but mostly early stages of bargaining.

Last week, the Elementary Teachers Federation of Ontario indicated it would be taking a strike vote among its members in the coming weeks.

The Ontario Secondary School Teachers' Federation has gone to the Ontario Labour Relations Board to determine which issues should be bargained centrally and which should be dealt with at local tables, and the union is waiting for a decision.

The talks are happening as the government has ordered school boards to start increasing average class sizes, with high school classes growing from 22 to 28 students on average over four years. Class sizes for Grades 4 to 8 will increase by one student per classroom, from 23 to 24.

The government has said that will mean 3,475 fewer teachers in the system over four years -- a staffing reduction it says will be achieved through not filling vacancies when teachers quit or retire.

Walton has previously said those cuts will trickle down, hurting educational assistant supports and custodial services provided by CUPE workers as well.

The Ontario Ministry of Education did not immediately respond to CUPE's statement Monday, but Education Minister Stephen Lecce said earlier he is disappointed that CUPE requested a no-board report.

"We continue to call on all parties to reach a deal in good faith, as soon as possible, to provide confidence and predictability to parents, students, and educators alike," he said in a statement Sept. 6.

Lecce has said he is open to negotiating a smaller boost to class sizes at the bargaining tables.

-- with files from Allison Jones