TORONTO -- The Liberal government is violating the collective bargaining rights of teachers and school support staff, four large unions charged Thursday as they launched a legal challenge of legislation that imposes a contract and freezes salaries for two years.

"Bill 115 was imposed before we had an opportunity to bargain in a meaningful way with local school boards," said Sam Hammond, president of the Elementary Teachers' Federation of Ontario.

"It goes far beyond any wage restraint or back-to-work legislation ever enacted in Ontario."

The bill, which passed last month with the help of the Progressive Conservatives, freezes wages for the majority of the union members while still letting younger teachers move up the salary grid. It also allows the government to impose its own agreement if it doesn't like what the unions and school boards negotiate together.

"We would not be standing here today if from the very beginning this government had sat down with us, in a respectful and fair way, and bargained with us," added Hammond.

Elementary and high school teachers have now completed strike votes across the province, but parents don't need to fear a labour disruption, said Ken Coran, president of the Ontario Secondary School Teachers' Federation.

"They should not be worried about a strike right now," said Coran.

"We said we want to collectively bargain. We're trying to relieve their fear."

The Ontario Public Service Employees Union said it just wants the government to allow time to reach collective agreements with local school boards, but will fight the legislation all the way to the Supreme Court if necessary.

"To the government I say wake up, smell the coffee, grow a spine, get honest and sit down and talk to us," said OPSEU president Smokey Thomas.

"That's all we're asking, or we'll take you into court and kick your collective asses all over the province."

Premier Dalton McGuinty, who recalled the legislature in August to pass the legislation and prevent teachers from getting automatic raises when their old contracts rolled over, wasn't surprised by the union's court challenge.

"We have a tremendous amount of confidence in the position that we have taken, and the law that we have adopted here in Ontario through working in concert with the opposition in the legislature," McGuinty said after a speech in suburban Vaughan.

NDP Leader Andrea Horwath warned the Liberals that legislation was unconstitutional, and said taxpayers will end up paying more if it is struck down by the courts.

"The worrisome thing is that in a couple years time we're going to get a big bill in the mail when the Supreme Court throws out this legislation and Ontarians have to pay the (teachers') back pay as well as the court costs for this expensive, wrong-headed move," said Horwath.

The government is confident the legislation will stand up to a constitutional challenge because unions were allowed to negotiate deals before it passed the bill. The unions representing teachers at Catholic and Francophone schools in Ontario did accept the government's original offer.

The Liberals recently unveiled proposed legislation to freeze the wages of 481,000 workers at hospitals, colleges, provincial agencies and the civil service, confirming the unions' fears that the teachers' wage freeze was just the first step.

"Let's be very clear, Bill 115 appears to be the beginning of a greater agenda to erode the rights of hard-working Ontarians," said Coran.

"McGuinty and (PC Leader Tim) Hudak have chosen to attack the rights of all Ontarians. We have chosen to stand up for the rights of all Ontarians."

The government said it needs a two-year wage freeze from more than 1.2 million public sector workers so it can trim a $14.8-billion deficit without laying off staff or cutting services.