A principal has said her school cannot take on any more pupils if plans for 130 new homes in the town are given the go-ahead.
Gaynor Yates, who is in charge of The Grange School in Daventry, made the comments after plans for new housing and a revamped college were revealed.
Northampton College is looking to transform its Daventry campus on Badby Road West with the new houses and a revamped college site.
She doubts that any families who move into the new homes would be able to get a place at the school.
Mrs Yates said: “We are oversubscribed and we have long waiting lists for every single year group. It is very difficult for parents to get a place at this school.
“We have a two-form entry which means that we have 60 children in each of the year groups.
“There is one year group which has 75 children in and we have three classes in that year group because we were asked to take that number on by the local authority.
“We do not have the physical space to take on any more children either. One of the reasons why we are such a good school is that we have a food technology area, an art studio and a music room and we wouldn’t want to compromise those areas in order to get more children.
“We do not have any space for the school to be extended either.
“We are also the designated catchment area for the Middlemore estate in Daventry. We have two very large housing estates to cater for and there would be no way we would be able to do it.”
Northampton College has been given £6.5 million by the Government towards the new building.
However, the college must match the same funds and the college says the only way to do this to use some of the land for housing development.
The project, which will cost a total of £13 million, will also see two full-sized football pitches and open space.
The plans have not proved entirely popular with many of the residents on the Grange estate concerned about the loss of green space around the site.
It has led to some forming the College Ground Action Group which has put in a community asset application in order to protect the green space from any development.
The application will then go to Daventry District Council (DDC) which will decide whether the playing fields are a community asset.
A DDC spokesman added that once an application is received the group will be sent an acknowledgement if it is valid and the owner will be advised.
There is then a period of up to eight weeks for consideration of the application before the property is listed.