WINDSOR -- Windsor-Essex teachers joined others across the province in a massive walkout.

About 6,100 teachers and support staff hit picket lines in 20 different spots in Windsor-Essex.

All four teachers’ unions are striking on Friday to back contract demands.

The labour groups say it marks the first time since 1997 that educators from all the major unions are walking out on the same day.

Liz Stuart, with the Ontario English Catholic Teachers' Association, says 200,000 teachers and education workers are calling on the government to back down on cuts.

The unions, particularly those representing secondary teachers, are upset about increases to class sizes, which they say will lead to thousands of fewer teachers in the system.

Harvey Bischof, president of the Ontario Secondary School Teachers' Federation, says today's demonstration will counteract the education minister's suggestions that teachers don't support their union leadership, and that parents aren't behind them.

Education Minister Stephen Lecce said the two million students out of class today should be in school instead.

"The focus of union leaders ought to be on negotiating a deal that keeps students in class," Lecce said in a statement. "Parents are losing patience with the union-caused disruption in their lives, the inconsistency in their children's education, and the financial impact of scrambling for alternate care."

With files from the Canadian Press.