The council says its schools are struggling and is blaming a drop in birth rates and people moving away because of Brexit.
There are more than 539 vacant places in reception classes since January.
The authority says continuing to reduce admission numbers alone will not be enough to tackle the scale of the problem.
Bosses say it’s an issue because government funding is allocated per pupil.
Residents are being urged to go onto the council website and share ideas on how rates could be improved.