An empty classroom is shown in this file image. (The Canadian Press)

Ontario's premier ramped up criticisms of the province's teachers on Thursday, demanding they resume regular work even as major unions forged ahead with widespread strikes.

Doug Ford targetted all four major teachers' unions during debate at the provincial legislature, which took place as educators marched around the building.

The unions representing Ontario's French-language and English Catholic teachers both held provincewide strikes on Thursday. Public high school teachers at nine boards also walked off the job as part of a series of rotating, one-day strikes.

The walkouts came two days after the Progressive Conservative government tabled proposals meant to address two long-standing union demands. Education Minister Stephen Lecce offered to increase average high school class sizes from 22 last year to 23 next year -- instead of the government's original target of 28 -- and allow an opt-out for e-learning courses the Tories previously said would be mandatory.

Ford said Thursday the moves should have paved the way to deals with the unions, but because it hasn't yet resulted in progress, it shows the real issue keeping the parties from an agreement is teachers' pay.

"My message to the unions is that the party is over with the taxpayers money," Ford said. "Pack your bags and get back into the classroom."

The teachers' unions have said they would not sign a deal that included class size increases and mandatory online learning -- two of the cost-cutting measures the government said were necessary to balance the books.

The province has offered teachers a one per cent pay increase, while the unions are asking for closer to two per cent.

Lecce said Thursday the government has made "reasonable moves" at the table that would effectively freeze class sizes, offer a parental opt out for online learning, and a commitment to full-day kindergarten.

"It's time for the unions to get off the lawn and get back to the table," he said.

Meanwhile, teachers with the Ontario Secondary School Teachers' Federation and Ontario English Catholic Teachers' Association carried banners and signs around the legislature Thursday morning, calling on the government to bargain in good faith.

OSSTF President Harvey Bischof said the government's latest offer would still result in the loss of nearly 1,800 teacher jobs and thousands of course offerings.

He said the government presented its latest position with "no flexibility", leading the union to conclude they could not return to talks.

"They clearly laid out, essentially, take it or leave it proposals that cut off any avenue to a deal," he said. "There are several aspects of what we were talking about they had established as essentially bottom lines with no flexibility."

Bischof said he believes parents continue to support the teachers in the tense contract talks, despite the new government position on class size and e-learning.

"I'm not concerned that the public will suddenly decide that they want to support cuts to the quality of their children's education," he said. "(Lecce is) still talking about cutting thousands and thousands of course options out of the system."

OSSTF currently has no dates scheduled to return to the bargaining table. Nor does the association des enseignantes et des enseignants franco-ontariens, the union representing French-language teachers.

OECTA was in talks with the government Thursday and did not immediately provide comment.

The Elementary Teachers' Federation of Ontario said it will escalate its job action toward the end of the month in light of the fact that no talks are currently scheduled with the government.

The union did not provide details on what form that escalation would take, but said it would not occur until March 23. It said more details would be released on Monday.

"We will do what it takes to stop the minister's rhetoric and get his negotiating team to come to the table with proposals that will result in a fair deal for students, student learning and educators," ETFO President Sam Hammond said in a statement.

NDP education critic Marit Stiles said the government needs to get back to the bargaining table.

"The minister keeps negotiating at a podium and a microphone and he should be at the bargaining table with education workers," she said.

Interim Liberal Leader John Fraser questioned whether the apparent change in government position is actually a concession at all.

"It still looks like they're making class sizes larger," he said. "It's unclear if the commitment they've made runs the length of the contract. It's one thing to say it, it's another thing to sit down at the table and say 'here are the words'."

Green party Leader Mike Schreiner said even a class size increase from 22 to 23 students will result in teacher layoffs and hurt students.

"The government has created chaos in our education system," he said. "I respect parents, teachers, students, education workers, for standing up and speaking out against it."

This report by The Canadian Press was first published March 5, 2020.