TORONTO -- TORONTO -- The union representing public high school teachers in Ontario is not ruling out further job action in the new year -- including a full strike -- if it can't reach a new contract with the province.

The president of the Ontario Secondary School Teachers' Federation President made the comments Wednesday as the union held its third one-day strike in as many weeks, closing high schools at 10 boards across the province.

Harvey Bischof said this will be the final job action held by the union in 2019, but future strikes could include a full withdrawal of services by the union's 60,000 teachers and education workers.

"We're not ruling anything out," said Bischof. "But the best possible thing for everybody concerned is that there's an agreement that creates stability and goodwill in the system."

No new talks are scheduled between the teachers and the government until January, when it's a government-appointed mediator is expected to invite both parties back to the table.

That mediator called off talks earlier this week, saying the government and union proposals remained too far apart.

Bischof said he hopes the holiday break will help everyone approach bargaining with renewed focus and will set the tone for the new year.

"It's very much dependent on what happens at the bargaining table when we get back," he said. "Whether or not this government is prepared to start bringing forward positions that support quality of education in this province."

Ontario's public high school teachers have been without a contract since August and have ramped up the pressure on Premier Doug Ford's government by walking off the job on three consecutive Wednesdays this month.

The first strike on Dec. 4 was provincewide, while the second on Dec. 11 affected nine boards.

The job action Wednesday impacted boards including Thunder Bay, Waterloo and the York Region, in the riding held by Education Minister Stephen Lecce.

Lecce said Wednesday that the repeated job actions are not constructive. He called on the union to bring new proposals to the bargaining table in January and not take further job action.

"Escalation by the teachers' union leaders is really effecting our kids," he said. "I think it's unfair that they're in this position. It's now the third time they've opted to walk out on kids when they have an obligation, I would argue, to ensure the continuum of learning for our students."

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

The government has said 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.

NDP Leader Andrea Horwath called on Premier Ford to convene a cabinet meeting over the holidays so that the government can rethink its strategy for education talks in the new year.

"Mr. Ford and Mr. Lecce don't seem to care that the chaos that they've created in 2019 is going to be with us again in 2020," she said. "The disruption in our kids' education and the concern and accommodation parents are going to have to make ... will happen again in January."

This report by The Canadian Press was first published Dec. 18, 2019.