TORONTO - Ontario's roughly 9,000 college instructors have given their union the green light to strike at the province's two dozen community colleges.

The Ontario Public Service Employees Union said Wednesday night that about 57 per cent of members who voted supported strike action.

The vote on whether to give their union a strike mandate came after five months of talks with the colleges broke down Dec. 15.

Ted Montgomery of the OPSEU bargaining team, which represents faculty members, said a walkout wouldn't happen for at least a month.

For the union, key issues are workload, academic freedom and management's decision in November to impose its offer on the teachers without a vote.

The colleges said in a release that their offer increases salaries by eight per cent over four years and raises the maximum salary to $103,975.

Training, Colleges and Universities Minister John Milloy urged both sides Wednesday night to keep the best interests of 200,000 full-time students in mind and return to the bargaining table as soon as possible.

"I am very concerned that the ongoing contract dispute between faculty and Colleges has the potential to interrupt classes for thousands of Ontario students," Milloy said in a release.

Workload was also the top issue when college teachers went on strike for three weeks back in 2006, Montgomery said.

The previous contract expired Aug. 31, 2009.

The union wants a 2.5 per cent pay increase in each year of a three-year contract.

Both sides have indicated they would like to resume talks.

Montgomery said OPSEU was in touch with the mediator following the vote.

"We hope management takes it seriously and we expect they will," he said.

Dr. Rachael Donovan, the chair of the colleges' bargaining team, said the colleges will be asking OPSEU to return to the bargaining table as soon as possible to work to avoid a strike.

"We are committed to negotiating a fair, affordable and practical settlement, which ensures that our students receive the highest quality of education possible," Donovan said.