Parents have stepped up their campaign to save Oaks After School Club in Hailsham.
Youngsters waved posters and banners in protest against the after school club being forced to shut as the county council aims to turn the building into a support service for vulnerable children in July.
Parents fear they will have to rely on friends to take care of their children if a replacement service is not found.
The club provides child care in Dunbar Drive from 3.30pm each day.
London worker Wayne Spicer has a child attending the club. He said: “We are a group of parents desperately trying to fight plans by East Sussex Council, who due to Government cuts and lack of space in the town, plan to close down our after school club which has been running for more than five years.
“As working parents we will have nowhere to send our children. “I don’t know what it will mean. We will have to rely on friends to pick them up or we will have to have conversations with to see if we can change shifts.
He added that Hailsham was an expanding town, with housing developments by Taylor Wimpey, Redrow and Charles Church, which would increase demand for an after school club service.
Fellow parent Sharon Castle said: “I’ve used it because my circumstances changed at home. It’s not an option to go part-time at because we would lose out financially then have to ask the state to help.”
The Oaks After School Club has operated from the site in Dunbar Drive since 2007 and currently has 24 children on its register.
It is Ofsted registered and cares for children from five primary schools in the area.
Parents and staff have failed to find alternative accommodation.
Debbie Adams, East Sussex County Council head of children’s centres services, said: “The council informed the after school club in July last year that we would no longer be able to offer accommodation for the club in Dunbar Drive.
“The club has had a year to find alternative accommodation, which we believe is a reasonable period of notice.
“The space currently used by the after school club is adjacent to premises used by our looked-after children’s service, and we need the space to provide a child-friendly environment for children looked after by the council to have contact with their parents.”