The union representing college faculty will be fighting the back-to-work legislation in court.
OPSEU president Smokey Thomas explained the union is launching a Charter challenge against the legislation that forced instructors back to work earlier this week, ending a five-week-long strike at Ontario's colleges.
College staff returned to work on Monday, with students going back to class on Tuesday.
The union's lawyers believe the province had other options.
Thomas suggests the filing is a matter of principle. He says the legal process is expected to take months and he hopes that if the union wins the fight, the province will agree to sit down and find remedies with the college bargaining process. The union has called for the College Employer Council to be disbanded.
About half a million students were affected by the strike.