MONTREAL -- The government announced Tuesday that high-school students throughout red zones may return to class on Monday -- but Montreal's biggest English-language school board says it's just not possible.

The English Montreal School Board told parents today that only Grade 9 students will return to class in person on Monday.

Students in grades 10 and 11 will continue with the same schedule they've had since the beginning of the year, the board said. The board said their return would be "staggered" and will let them know more next week.

“A communication with more details will be sent next week once we feel we are ready to welcome everyone back safely," said board chair Joe Ortona on Thursday.

The EMSB said earlier this week that its administrators would meet Wednesday to come up with a plan to put in place for Monday. It was already pretty clear it wasn't enough time, said board spokesman Mike Cohen.

"It's not one-size-fits-all," said Cohen.

"Can they all be ready for Monday? Is it feasible? We're going to find out, and we're hoping on Thursday that we'll have a better, clearer picture on how we'll proceed."

It's unclear if the same will go for other schools in the Montreal area. Other boards are still coping with the surprise announcement and haven't said if and when students will return.

--With files from CTV's Luca Caruso-Moro