TORONTO -- Teachers should resolve their dispute over pay with the governing Liberals in court, not by depriving students of extracurricular activities, Premier Dalton McGuinty said Tuesday.

The Ontario Secondary School Teachers' Federation said it's possible that teachers could withdraw from voluntary activities for two years in protest of a controversial anti-strike law that allows the government to impose a new collective agreement.

"It's something that we're not ruling out, and it really is dependent upon how the current government or the next government -- or the next premier -- handles the situation around Bill 115," said Paul Elliott, the union's vice-president.

But McGuinty, who has now characterized the dispute as a "disagreement over pay" said he doesn't understand why elementary and high-school teachers are involving students by stopping voluntary activities and staging one-day strikes.

"It's one thing for teachers to withdraw their goodwill from us, but it's another thing to withdraw the goodwill from students," he said.

"I think students have to be able to count on those extracurricular activities. They are such an important part of an enriched educational experience."

But he said he won't make extracurricular activities mandatory.

"You can't pay for goodwill," McGuinty said. "You can't legislate goodwill."

The Progressive Conservatives say they'd consider making the activities mandatory.

"I think that we need to look at that and do something about it," said education critic Lisa MacLeod.

The unions say the job action isn't about money, but the legislation that violates their constitutional rights. Four unions have joined forces to take the government to court over the law.

But McGuinty said a deal is still possible before the end of the year, since his government managed to strike an agreement with Ontario doctors after a "bumpy and very rocky road" over pay which also sparked a lawsuit. It also reached a deal with Catholic and francophone teachers this summer.

If teachers don't reach local deals with their school boards by Dec. 31, the province will impose one that will freeze the wages of most instructors and cut their benefits, such as the number of sick days they're allowed to take each year.

What teachers will do if a contract is forced on them "remains to be seen," Elliott said.

"With the unprecedented powers that have been given to the Ministry of Education, we're not exactly sure what rules are going to be followed come Dec. 31," he said.

Teachers could strike, he said. "At some point ... we could possibly decide on a full withdrawal of services, but it really is dependent upon the decisions that the minister of education makes."

Instead of involving students in the dispute, teachers should leave it to be settled in the courts, he said.

"Don't deprive Ontario students of everything that you bring to the table every day, what you've brought to the table every day during the course of the past nine years," McGuinty said.

"Keep that going. Bring that to schools every single day."

But many high-school students who walked out of class Monday have sided with their teachers in the dispute.

They should get kudos for it, said Elliott.

"They appreciate the jobs that they do, they appreciate all the voluntary work that they do," he said.

"And they would like to see the politics that have been imposed on this through Bill 115 gone and just let the teachers get back to teaching."

Public elementary teachers have started rotating one-day strikes, which are expected to roll out across the province before Dec. 20.

They began Monday in the Stratford and Timmins area and spread Tuesday to Niagara and Keewatin-Patricia in northwestern Ontario.

On Wednesday, teachers in Ottawa-Carleton, Lakehead in Thunder Bay and Hastings-Prince Edward will walk out. Three other school boards -- York Region, Trillium Lakelands and Renfrew -- will see their teachers go on strike on Thursday.

Those in Simcoe County, Kawartha Pine Ridge near Peterborough and Upper Grand around Guelph will walk out on Friday.

McGuinty said he won't intervene as it's a "small price to pay" to protect smaller class sizes and the roll out of full-day kindergarten, rather than spending the money on pay hikes.

The self-described "education premier," who can no longer boast of maintaining labour peace in Ontario schools, dismissed the notion that the current strife wasn't the legacy he wanted to leave.

McGuinty is stepping down as premier at the end of January, once a new Liberal leader is chosen.

"It's not about anybody's legacy, it's about doing the right thing today for students and for teachers and for education in Ontario," he said Tuesday.

NDP Leader Andrea Horwath, who wants to repeal the legislation, said she warned him months ago that the bill would backfire and exacerbate an already tense situation with teachers.

"And now the premier is rewriting history -- rewriting history to make it sound like this is all about a pay cut," she said.

"That's not what this is about. ... I think it's shameful that this government has put us where we are now."