An Ontario judge has found that the provincial government "substantially interfered" with teachers' right to collective bargaining.

The governing Liberals imposed contracts on teachers in 2012 amid a growing threat of strikes. The contracts froze wages for some teachers, limited their ability to strike and ended payouts for unused sick days.

Several unions took the government to court, arguing that Bill 115 violated their constitutional rights.

Ontario Superior Court Judge Thomas Lederer issued his decision today, ruling in favour of the unions.

Sam Hammond, the president of the Elementary Teachers' Federation of Ontario, says the decision "is a total vindication" of the union's "pursuit of democratic rights."

Paul Elliott, president of the Ontario Secondary School Teachers' Federation, says he is pleased the court "re-confirmed the importance of free, fair and meaningful collective bargaining."

A spokesperson for Education Minister Liz Sandals says in a statement that minister is reviewing the decision.

The judge has left it up to the unions and the government to discuss what the remedy should be.

"I find that considering the overall process undertaken, the actions of Ontario substantially interfered with meaningful collective bargaining," he wrote.

"It is telling that although all sectors were experiencing the same fiscal concerns, Ontario allowed for free negotiations and did not interfere with collective bargaining in any other sector."

The results of the case are expected to have strong implications for the power of governments in Canada to dictate the terms of union contracts and to take away the right to strike.