TORONTO -- Ontario is cutting the amount of money school boards receive per student, which advocates say will mean fewer services and supports for kids.

The Progressive Conservative government announced 2019-20 school board funding Friday, details that came as some boards have been issuing surplus notices to teachers, prompting worries about layoffs due to increasing class sizes.

Overall funding to school boards will be $24.66 billion, up slightly from $24.53 billion this year. But higher enrolment means will boards get an average of $12,246 per pupil, versus the $12,300 they got in this school year.

Education Minister Lisa Thompson downplayed any negative effects because of that per-student decrease.

"The (funding) on a per-pupil basis is essentially an average and it doesn't reflect the direct impact in the classroom," she said. "We need to take a look at the holistic picture and I feel very good in the path that we've taken and set out with our proposed plan."

Cathy Abraham, the president of the Ontario Public School Boards' Association, said the boards will determine individual impacts over the coming weeks, but the decrease in per-student funding is a concern.

"We know that it's not costing less to educate children," she said.

The chair of the Toronto District School Board said Friday's announcement will mean an estimated $21.2 million funding reduction for them.

"As a result, we are looking at one of the most challenging budgets in years and in the weeks ahead, difficult decisions will have to be made," chair Robin Pilkey said in a statement.

Harvey Bischof, president of the Ontario Secondary School Teachers' Federation, said the government's plan for education will mean fewer teachers, learning opportunities and supports for students.

"What you're seeing there is a reflection of the intended cut in services for students," he said. "The overall envelope doesn't keep up with a combination of inflation and enrolment growth."

While the amounts of some specific grants and funds will increase, such as special education and Indigenous education, others are being cut or eliminated entirely.

A grant given to boards with higher numbers of at-risk students is being cut by $230 million, to $514 million.

The pupil foundation grant -- which is the largest single component of the school board funding and is used for salaries of teachers, early childhood educators, and other education workers -- is $633 million lower than last year.

That cut comes after Thompson announced last month that high school class sizes will increase from an average of 22 to 28 over four years, and average class sizes for Grades 4 to 8 will increase by one student per classroom. School boards have said the increase means thousands of teaching jobs will be lost, but the government has insisted that can be done through attrition.

To that end, the government has established a four-year, $1.6 billion fund to top up boards that don't get enough teachers retiring or otherwise voluntarily leaving to cover the difference in staff needed due to larger classes.

Along with larger class sizes, Thompson also announced last month that students will need to complete four e-learning courses. Some boards have expressed concerns that online courses might not be right for all students, and that in rural areas students may not have reliable internet.

Boards have also said the class size changes will lead to fewer courses being offered, such as in the arts, and some have already told students they will have to re-select their courses for the fall.

NDP education critic Marit Stiles said the latest funding amounts to a cut because it fails to keep pace with inflation and lowers the per-student funding.

"These cuts will hurt students, education workers and families," she said in a statement. "Classrooms will be overcrowded, programs will be cut and students will have even fewer opportunities and resources."

Several funds that the former Liberal government negotiated as part of education contract extensions -- to the tune of $281 million -- are being eliminated as contracts expire on Aug. 31.

The local priorities fund put money toward educational assistants to support children in need, at-risk students and adult education. The amounts for adult day school teachers will be funded elsewhere, but whether that funding as a whole continues depends on the upcoming contract negotiations, which could start as early as Monday, the government said.

Laura Walton with the Canadian Union of Public Employees, which represents 55,000 education workers, said that money funded 2,500 educational assistants, custodians and clerical staff.

"We know that will be an absolute attack on education workers throughout the province," she said.

Thompson called CUPE's prediction of layoffs speculative and disappointing.