Toronto high school students could be out of class as early as next month if their teachers can't settle on a new contract agreement with the public school board.

Talks between the Toronto branch of the Ontario Secondary School Teachers' Federation and the Toronto District School Board stalled Tuesday. The two sides have been negotiating since November.

The federation has refused to let its members vote on a contract offer that stipulates eight minutes of extra supervision time each day. Under the current contract, teachers' hall duty is limited. Principals are also limited in how many times they can ask their staff to fill in for an absent colleague.

The union says the new stipulation cancels a provision teachers have fought hard for in the past.

However, the board says that in order to keep schools safe, students need extra supervision.

A vote on the board's contract offer would have meant extending negotiations past Thursday's midnight deadline.

"We are disappointed that (the) provincial OSSTF has refused to allow Toronto secondary teachers to vote directly on the board's offer," said TDSB Chair John Campbell in a news release.

"We are still hoping to work towards achieving a local collective agreement prior to the deadline of Thursday, February 5," he added.

Toronto teachers are the only ones in the OSSTF that have yet to reach an agreement on the non-monetary terms of their contract. A province-wide deal on financial benefits has already been agreed upon.

The TDSB news release said the contract offers a 12.55 per cent raise for teachers, enhanced benefits, more teachers and reduced class sizes.

Talks between the board and the federation are expected to continue Wednesday but both sides say they are standing firm.

Some students say they just want an agreement to be reached before they have to pay the consequences of labour action.

"I'm trying to get all of my credits right now and if I lose any bit of study time where they could be teaching me I'd fall behind," one teen told CTV Toronto Wednesday afternoon.

"There is so much uncertainty in the school system," said another young man adding that he finds it hard to know which side to trust.

Queen's Park has said that if an agreement between the two sides is not reached by the deadline, it will withdraw funding for a 12 per cent raise over four years. Instead, it will only fund a two per cent raise for two years. Other benefits would also be lost.

The provincial government recently had to step in between administrators at York University and their contract faculty with back-to-work legislation after the two sides failed to reach an agreement after nearly three months of job action.

With a report from CTV Toronto's Andria Case