Catholic schools across Ontario will be closed today, as will public high schools and elementary schools in several boards.

The union representing Catholic teachers is holding a one-day strike today, while the other two unions are engaged in rotating strikes.

Liz Stuart, president of the Ontario English Catholic Teachers Association (OECTA), says there are some 45,000 teachers picketing around the province.

"Our students deserve a government that invests in them and their future," she said.

All three unions, as well as the one representing teachers in the French system, say they are frustrated with a lack of progress in contract negotiations with the provincial government.

Stuart says the government has presented a hard line that it hasn't moved on.

"We need them to authorize their bargaining team to actually bargain," Stuart said.

The unions say class size increases and the introduction of mandatory e-learning courses are among the sticking points, but Education Minister Stephen Lecce says compensation is the main barrier.

Some 45,000 teachers are picketing today across the province for a one-day strike. (Michael Charles Cole/CBC)

Patricia Minnan-Wong, a member of OECTA and the past president of the Toronto Elementary Catholic Teachers, said the union is asking for a cost of living wage increase, but their main focus is on reversing cuts to education the province has made.

In the meantime, Minnan-Wong says the union is eager to get back to negotiating.

"We would rather be at the table bargaining than out on these streets today," she said.

Last week, Lecce announced that the government will offer parents money for childcare costs incurred during the strikes.

Parents can apply for amounts from $25 to $60 per day for children under 12.

NDP leader Andrea Horwath joined teachers at the picket lines during the strike. (Michael Charles Cole/CBC)

Opposition leader Andrea Horwath, who joined the teachers at the picket lines Tuesday, says the offer is a political ploy.

"I think the government is trying to basically buy parents' support with their own money," she said.

"But I think parents have been pretty clear. They want their kid to have a quality education."

Stuart said the government should focus on finding solutions at the bargaining table, instead.

"If they would just put a fraction of the time and energy they spent coming up with that scheme into actually sitting at a bargaining table with us, we could probably have this resolved," said Stuart.

Horwath thinks the Ford government should scrap the cuts and get back to bargaining.

"The cuts are very clearly the barrier to progress on negotiations and if they really want negotiations to continue and to prevent further loss of classroom time for our kids, then what they need to do is take those cuts off the table," she said.

Boards targeted today by the Ontario Secondary School Teachers' Federation include:

Toronto District School Board.

Rainy River District School Board.

Simcoe County District School Board.

Near North District School Board.

Grand Erie District School Board.

Trillium Lakelands District School Board.

Hastings and Prince Edward District School Board.

The Elementary Teachers' Federation of Ontario is also striking at the Grand Erie and Trillium Lakelands boards, as well as the Renfrew County District School Board and the Superior-Greenstone District School Board.