There will be no extra-curricular activities for some Ontario students when they return to the classroom this fall unless a deal between their school boards and the teachers' union is reached over the summer.

In a bulletin addressed to members of the Ontario Secondary School Teachers' Federation, the union said it will be in a "legal central strike position" in July.

"Please be advised that as soon as OSSTF/FEESO is in a legal central strike position we will be notifying all members to immediately cease performing any and all extra-curricular activities as of that date."

The OSSTF represents approximately 60,000 public high school teachers, occasional teachers and education workers.

A similar letter was also sent to members of the Ontario English Catholic Teachers Association (OECTA) earlier this month.

According to the June 8 bulletin, talks with the provincial government and the Ontario Catholic School Trustees' Association have, so far, been frustrating.

"Progress has been exceedingly slow and one of the major issues has been addressed," the letter said. "Given the current state of negotiations and all of the unresolved contract strips, we will continue to plan for job action in September."

The union said mediated talks are expected to resume from June 22 to June 26.

The OECTA represents approximately 50,000 educators who teach in English Catholic schools in Ontario. Its members voted 94 per cent in favour of a strike mandate in April.

This latest development in Ontario's labour strife in both public and catholic schools comes after the provincial government in May passed back-to-work legislation, which ensured public high school teachers in the Durham, Rainbow and Peel districts couldn’t strike for the rest of the school year.

Teachers in all those boards were on strike for weeks, keeping more than 70,000 students out of the classroom.