Thousands of Ontario public high school teachers are poised to walk off the job for one day today after contract talks between their union and the provincial government failed to produce an agreement.

Members of the Ontario Secondary School Teachers' Federation (OSSTF) left the bargaining table at midnight.

"Sadly, the [government's] bargaining team chose not to meet with us in the days leading up to our strike deadline. Our one-day job action will occur," OSSTF president Harvey Bischof tweeted. "#OSSTF education workers & teachers will be back in schools Thursday, we remain ready to negotiate."

Bischof, flanked by members of the federation's provincial executive during a news conference shortly before the deadline, said the government had not presented any new proposals in the past four days of bargaining at a downtown Toronto hotel.

Sadly, the <a href="https://twitter.com/Sflecce?ref_src=twsrc%5Etfw">@Sflecce</a> bargaining team chose not to meet with us in the days leading up to our strike deadline. Our one-day job action will occur. <a href="https://twitter.com/hashtag/OSSTF?src=hash&ref_src=twsrc%5Etfw">#OSSTF</a> education workers & teachers will be back in schools Thursday, we remain ready to negotiate. <a href="https://twitter.com/hashtag/onted?src=hash&ref_src=twsrc%5Etfw">#onted</a> <a href="https://twitter.com/hashtag/onpoli?src=hash&ref_src=twsrc%5Etfw">#onpoli</a> —@HarveyBischof

"We came to the hotel on Saturday morning four days ago with hope, hope that the government would finally move forward with proposals that are good for Ontario students," Bischof said.

"Over four days of bargaining, the Ford government did not forward a single proposal to secure quality of education for Ontario students, not a single proposal to protect class sizes [and] not a single proposal to ensure students have access to the support staff that some of them require to be successful."

It is expected the one-day strike will close a number of secondary schools across the province.

According to the union, the main issues in the dispute are government plans to increase class sizes and introduce mandatory e-learning courses. According to the government, the prime issue is compensation.

Both sides held separate news conferences on Tuesday evening, with the union and province accusing each other of being unreasonable.

Ontario Education Minister Stephen Lecce calls the strike a 'needless escalation.' (CBC)

Ontario Education Minister Stephen Lecce said the strike would be "needless escalation," and urged the union not to have members walk off the job.

"Our government has remained reasonable at the negotiating table, with the objective of keeping students in class," Lecce told reporters.

The union, which represents 60,000 members, says it is fighting to reverse cuts to classrooms that it says are harming students' ability to get a good quality public education. The teachers are already conducting a work-to-rule campaign.

Bischof said a one-day strike is "nothing" compared to the possible damage that could happen to the education system through new government proposals under Premier Doug Ford.

But the minister said since the province first began bargaining, the union has not made any "substantive moves" to reach a deal. He said the union is insisting on a $1.5-billion increase in pay and benefits.

"The onus is on OSSTF to be reasonable, stay at the table, and to cancel this needless escalation that is hurting children, parents and families," Lecce said.

Hundreds of teachers and support staff from Ontario secondary schools will strike. (CBC )

All day Tuesday, contract talks appeared to be at a standstill.

Earlier, Lecce had said his bargaining team had presented a new "framework" to negotiators for the OSSTF in an attempt to keep all parties at the table, but that's disputed by the union.

Teachers have been without a contract since August.

Some of the province's largest school boards have said they will be forced to close high schools if the job action takes place. The Toronto District School Board and the Peel District School Board, west of Toronto, have confirmed their secondary schools, Grades 9 to 12, will be closed to students on Wednesday.

Boards where the OSSTF also represents education workers, such as the Waterloo Region District School Board and Ottawa-Carleton District School Board, will close both high schools and elementary schools should there be a strike.

Bischof said he is sympathetic to parents who would be inconvenienced.

"I can tell you that the long-term damage to the system, if we allow this government to continue to go down this destructive path, is far worse than a day lost to labour action," he said earlier.

Lecce said the main issue in talks is compensation. The government recently passed legislation to cap annual wage increases for all public sector workers at one per cent for three years. The union is asking for inflationary increases, which would amount to about two per cent.

In addition to public high school teachers, the OSSTF represents occasional teachers, educational assistants, continuing education teachers and instructors, early childhood educators, psychologists, secretaries, speech-language pathologists, social workers, plant support staff and university support staff.