The Ontario Secondary School Teachers Federation says its members will be on the picket lines Monday after talks fell flat late Friday.
It means 24,000 students in the region east of Toronto, that includes Ajax, Whitby, Pickering and Oshawa, will be staying home.
The two sides say no talks are scheduled and the Durham District School Board said that it had no choice but to close schools on Monday out of concern for student safety.
School board chairman Michael Barrett issued a statement on Saturday expressing disappointment that the teachers have opted for "the picket line rather than the negotiations table."
Education Minister Liz Sandals said in a statement on Sunday that the government is committed to a bargaining process that is in line with their fiscal plan.
"Parents and students in Durham face significant disruption as the result of a teachers' strike and I encourage both sides to return to the bargaining table," Sandals said.
"We are committed to staying at the central table to do that and encourage all local parties to reach negotiated local agreements," she said.
The Ontario Secondary School Teachers Federation issued a statement Saturday night, accusing the school board of "punitive micro-management of teachers' professional lives."
"This employer's refusal to engage in real negotiations has really left us no option," said Dave Barrowclough, president of the teachers local in the district.
"They refuse to enshrine in the collective agreement even language that would clearly enable us to improve our teaching practices."
It's the first round of negotiations since the province brought in a new bargaining system, with both local and provincial talks.
Progressive Conservative education critic Garfield Dunlop says the Liberal government had given Durham teachers no other option than to strike.
"The people who are being harmed are the students and their parents," Dunlop said in a statement on Sunday. "We urge both sides to focus on the students and get back to the bargaining table."
The government faces more disruption in provincial schools as the Elementary Teachers' Federation of Ontario, which applied for conciliation in late March, asked for a "no board report" Monday, signalling that talks with the province are at an impasse.
The union would be in a legal strike position 17 days after the report is issued.
"The government and (the Ontario Public School Boards' Association) appear intent on eroding our existing rights and taking us back to the bad old Mike Harris days," the union said in a statement, referring to the former Tory premier whose relations with the unions deteriorated in the '90s.
"They do not appear to be serious about finding a reasonable way to resolve this collective agreement which has been expired now for eight months. Instead, they are provoking a crisis."
It's been three years since the Liberals forced contracts and wage freezes on the teachers through legislation, angering the unions, and the relationship has since slowly improved.
However, as the Liberals try to eliminate a $10.9-billion deficit through measures that include "net zero" increases in contract negotiations, dissent appears to be brewing — although the teachers say wages are not the only issue.