Public high school teachers in Ontario hit the picket lines Wednesday for their third job action in as many weeks.

Educators represented by the Ontario Secondary School Teachers' Federation are holding another one-day strike in a bid to ramp up pressure during contract talks with the government.

The strike is affecting these 10 boards across the province:

York.

York Catholic.

Halton.

Lakehead.

Thunder Bay Catholic.

Lambton Kent.

Thames Valley.

Waterloo.

Waterloo Catholic.

Kawartha Pine Ridge.

The union says it is pressing the government to reverse increases to class size and mandatory e-learning requirements.

"The cuts that Stephen Lecce and Doug Ford are making to our schools have cost our board in the last year alone 118 classes for our kids," said Muna Kadri, vice-president of the OSSTF.

President of OSSTF Harvey Bischof at the picket lines with teachers in their third one-day strike. He says he hopes the government will start listening to the parents they consulted who say they don't want larger class sizes or mandatory e-learning. (Michael Wilson/CBC)

President of OSSTF Harvey Bischof was also out on the picket lines today. He said parents also voiced their concerns during consultations with the government.

"I hope they start to listen to the parents who told him in their own consultations that they don't want larger class sizes. They don't like mandatory e-learning. They want their children to have access to the support staff that give those kids an equitable shot at success in our school system," he said.

The government says the main issue is compensation, as the province attempts to cap public sector salary increases at one per cent. The union is asking for increases of approximately two per cent.

Teachers who are part of OSSTF are on strike for the third time. Talks with the government have been put off until 2020. (MIchael Wilson/CBC)

Yesterday, Lecce called those negotiations "frustrating" and "disappointing."

A government-appointed mediator has called off talks between the parties until the new year, saying their proposals remain too far apart.