TORONTO - Once the best friend of Ontario teachers, Premier Dalton McGuinty is now in a full-blown battle with the province's public school educators - and the first casualty will be extra-curricular activities.

Unions for the province's public elementary and high school teachers - outraged over the passage Tuesday of Bill 115 - have asked their members to reconsider volunteering for after-school activities such as clubs and sports.

"We're going to fight this one all the way," Ken Coran, president of the Ontario Secondary School Teachers' Federation (OSSTF), said, announcing that his members will be urged to participate Wednesday in a one-day ban on extra curriculars.

Sam Hammond, president of the Elementary Teachers' Federation of Ontario (ETFO), said his members would be advised to "take a pause" on extra-curricular activities.

ETFO also wants its members to take part in "McGuinty Mondays," in which teachers and educational professionals will refuse to take part in school or system-level meetings.

CUPE Ontario announced it would launch a constitutional challenge on the grounds that the bill interferes with collective bargaining.

McGuinty - known as the "education premier" for dramatically ramping up investments in the sector and for implementing full-day kindergarten and class-size caps after a period of prolonged labour strife under Mike Harris - was repeatedly criticized by the unions.

"There is no education premier," Hammond said.

Bill 115, the Putting Students First Act, gives teacher and school staff 0% increases, partially freezes the salary grid, eliminates sick day banks and bans strikes for two years.

Teachers argued the bill goes well beyond that to give cabinet, rather than the legislature, the right to restrict strikes and lockouts, to extend the bill beyond two years and to approve or change contracts negotiated with local school boards.

"This cynical, illegal, unjust law is a problem for all of us," said Fred Hahn, president of CUPE Ontario.

McGuinty said he rejected the idea of a social contract, as introduced by the Bob Rae NDP government, and believes his bill will withstand legal scrutiny because an attempt was made to bargain with the teachers and school staff representatives.

The battered provincial treasury cannot afford to give broader public sector workers, including teachers, a pay increase right now without giving up improvements such as full-day kindergarten, McGuinty has said.

"Families are saying to us, 'Give our kids a quality education and give us a strong economy so my child, when she grows up, has access to a good job,' and that's what we're delivering on," McGuinty said.

Bill 115 is based on a deal already negotiated and signed between the Ontario English Catholic Teachers Association (OECTA) and the McGuinty government.

Liberals and Tories teamed up to get the bill passed, while the New Democrats voted against it.