Northamptonshire County Council has proposed closing the Grange home and moving its residents into the privately run Longlands on the Danetre Hospital site.
However, Cllr Wendy Randall, leader of DDC’s Labour group, says it means services at Longlands will be cut.
She said: “Currently Longlands has 15 dementia care spaces, with the rest dedicated to respite and rehabilitation care. If the move goes ahead we were told at the meeting that the respite care and rehab care will go.
“I know a lot of people use the respite care at Longlands. The facilities and care there are so good. If that option is removed those families who use them will have to go elsewhere. There are other homes in Daventry that offer that service, but it’s disruption to vulnerable people’s lives.
“The rehab care is for people who have say suffered a stroke and don’t need to be in hospital, but are not ready to go home. If that goes from Longlands the nearest facilities are in Northampton or Rushden. That would mean partners, children and friends, travelling a long way to visit.
A county council spokesman said: “Individuals currently at the Grange would have the choice of where they would like to move to. If converted, Longlands would be one of the alternatives available, and would provide them with better quality, modern care home facilities.
“No decisions have been made and we welcome feedback to help shape the proposals. We understand that change can be difficult and will work with all residents, their families and staff to help them through this process.”