After nine years of labour peace in Ontario schools, the Elementary Teachers' Federation has voted 93 per cent in favour of holding a one-day political protest.
McGuinty has asked teachers to accept a "real two-year wage freeze" as part of recent austerity measures.
Ontario teachers start at $41,766 to $44,292, and can make up to $92,813 in elementary schools and $94,942 in secondary schools, depending on years of service and education.
The government wants to freeze the grid so no one gets a raise because of seniority or improved credentials.
The union says it will stage a massive demonstration in Toronto if Premier Dalton McGuinty's government tries to legislate a wage freeze for teachers.
The last time that happened was in 1997 when Mike Harris was Premier.