TORONTO -- The Ontario government will be tabling back-to-work legislation this afternoon for striking secondary school teachers.

Education Minister Liz Sandals says a branch of the Ontario Labour Relations Board has ruled that strikes by high school teachers in three boards are putting the students' school years in jeopardy.

More than 70,000 students have been kept from class for between three and five weeks due to the strikes in the Sudbury-area Rainbow District, Peel Region and Durham Region.

Sandals says she wants to get kids back into class as quickly as possible and that unanimous consent is needed from all parties to get the legislation passed today.

She says she respects the professionalism of teachers and the collective bargaining process, but it's important to ensure students are able to complete their school years.

While the striking secondary teachers in three boards are set to be legislated back to work, their central union said this weekend that talks with the provincial government have reached an impasse.

The Ontario Secondary School Teachers' Federation plans to apply to the provincial labour ministry for conciliation -- the teachers must first use the government third-party assistance to try to reach a contract before they can take provincewide strike action.

The Ontario Labour Relations Board had also been set to rule on whether the three local strikes were illegal.

This is the first round of negotiations under a new bargaining system the Liberal government introduced last year, separating the process into local and central talks. The school boards argued that the three local strikes were really on central issues such as class sizes.