No further contract talks are scheduled between high school teachers and the government, and the head of the teachers' union says a one-day strike Wednesday is a "virtual certainty."

The Ontario Secondary School Teachers' Federation and the government had been scheduled to bargain Monday and Tuesday, but the mediator decided there was no point in continuing Tuesday.

Union president Harvey Bischof says the mediator decided that the two sides were so far apart that forcing a second day of talks would be more frustrating than productive.

Talks likely won't resume until the new year.

In extreme southwestern Ontario, high schools in Chatham-Kent and Lambton County will be closed, but schools in the Greater Essex County District School Board will be open.

With no progress on the horizon, Bischof says Wednesday's planned one-day strike in select school boards will almost certainly go ahead.

Education Minister Stephen Lecce is calling on them to cancel the strike and put forward new proposals at the bargaining table, which he says they have not done.

This report by The Canadian Press was first published on Dec. 17, 2019. With files from CTV Windsor.