Both Ontario PC Leader Tim Hudak and NDP leader Andrea Horwath were in Ottawa Tuesday to speak at the Association of Municipalities Ontario conference.
Both leaders addressed the general economic state in the province during their speeches.
But each politician was questioned about the Liberal legislation forcing an early return to work for Ontario MPPs.
This comes as Education Minister Laurel Broten expressed confidence the legislation, if passed, could withstand a court challenge.
Teachers unions threaten court challenge
Two unions who oppose the deal say they will challenge the legislation in court if it becomes law.
But the minority Liberals still need the help of one of the two opposition parties to pass the bill.
The New Democrats say it will spark a lengthy court battle that will cost taxpayers millions of dollars.
Andrea Horwath made a quip about the legislation, which is called "Kids First". She instead said it should be called "Liberals First".
She accused Premier Dalton McGuinty and his party for aiming at more seats instead of looking to have children return to the classroom on time in September.
Queen's Park resumes early
Tim Hudak also said the Liberal legislation to force teachers to take a wage freeze needed to have "teeth" if he was to support it.
The Ontario legislature will return to work two weeks early on Aug. 27 to introduce the bill that would impose a two-year deal on tens of thousands of teachers in elementary and secondary schools, government house leader John Milloy said Monday.
If the bill were passed, the government would also have the power to ban a strike or lockout for the next two school years.
The legislation is a last resort, Premier Dalton McGuinty has said. He also spoke at the conference in Ottawa, but on Monday.