Camapaigners fear plans for a new school at Allerton Grange in Leeds could rob the community of much-needed playing space.
Education Leeds is considering building on fields near Allerton Grange High School as part of an extension of primary school places in the city.
Consultation into a raft of proposals to create more primary school places will be held early in the New Year.
Charlotte Brtton, chairman of the Friends of Allerton Grange, a community group, said they appreciated the need for more school places but said it was important playing space was preserved for the community.
She said: "In the area we have lost six playing fields to residential and educational developments in the past 15 years. The Allerton Grange playing fields are the last fields in the area and Education Leeds are still intent on proceeding with the building of the modular school extension and not protecting the fields, which is a real disappointment."
An Education Leeds spokesman said: "There is an increasing need for additional primary school places in Leeds and we have a statutory responsibility to ensure there are enough to meet demand.
"We have met with the group and local ward councillors and assured them that if a new school is built, the associated playing field would be available for community use outside of school hours and the rest of the site that's not needed would be handed back to the council.
"It's important all views are considered and the consultation is the best way to ensure all opinions are aired. There will be a report to the council's executive board in March on the consultation outcome."