The Ontario government says it will partially walk back plans to increase high school class sizes in the province.

Education Minister Stephen Lecce made the announcement at a news conference Thursday afternoon.

Lecce says the government will scale the funded average class sizes back to 25 from the 28 it has been proposing for months.

However, the new proposal is higher than the previous funded average of 22.5 students per class.

The issue was one of several causing tension between the government and the union representing high school teachers that's currently trying to ink a new labour deal.

The Ontario Secondary Schools Teachers' Federation (OSSTF) said Lecce's announcement does not represent a meaningful step toward a new deal.

"Making things not as bad as they previously announced is not, in my mind, a concession," said Harvey Bischof, OSSTF president.

Bischof said the province's new proposal also includes an elimination of individual class size caps in local collective agreements, which he called "a massive step backwards."

While the province would hire one teacher per 25 students under the proposal, he said some classes could actually be much larger if those caps were eliminated.

"That doesn't speak to how those teachers are allocated and the size of the classes that they teach," he told CBC Toronto by phone.

Lecce says the move is meant to prove the government's commitment to averting strikes and keeping students in class.

The province's contracts with all school workers expired at the end of August, and unions representing both elementary and high school teachers have requested conciliation during the tense contract talks.