The Ontario Secondary School Teachers' Federation says its 60,000 members will step up their protest against Bill 115 by withdrawing from extra curricular and sports activities starting next Monday.
Union president Ken Coran says the high school teachers will not join their counterparts in elementary schools who plan one-day rotating strikes.
Coran says the Liberals need to repeal the controversial legislation that allows the government to impose a contract on teachers if it wants them to accept new deals.
He says the union has always been willing to accept a wage freeze, but feels the legislation strongly infringes on their right to collective bargaining.
Education Minister Laurel Broten says she will use the powers under the legislation to stop any strike actions once the threats turn into reality.
Broten blames the union leaders, not teachers, for the impasse, saying the unions seem set on strike action and are determined not to allow local contract agreements with a real wage freeze.
The OSSTF cut off talks last week after teachers rejected local agreements with two school boards, and cancelled future ratification votes.
The Elementary Teachers' Federation of Ontario is promising to give 72-hours notice before any rotating, one-day walkouts.