Campaigners want a “full independent review” of plans to downgrade Chipping Norton Community Hospital.
They have asked the Oxfordshire Joint Health Overview and Scrutiny Committee to refer the case to the Secretary of State for Health.
It came after Oxfordshire County Council agreed for beds at the hospital to be provided by care home provider the Orders of St John Care Trust rather than the NHS to save £240,000.
The hospital looks after patients who no longer need to be in an acute hospital, but are not yet fit enough to go home.
Clive Hill, of Chipping Norton Hospital Action Group, said documents it had obtained from the council under the Freedom of Information Act raised ‘some serious questions’ over the process it took to change care provider.
Mr Hill said: “For example, why does OCC deny our hospital is a community hospital and why was the sub-acute specification for our beds downgraded with no public consultation.
“We are making no allegations against OCC or any of its officers but we feel the documents we have obtained under the freedom of information requests show there are some serious questions to be answered.
“We believe by far the best way to get at the whole story behind what has happened and why is to have the case called in by the Secretary of State for a full and independent review and we hope that OCC will not oppose our request.”
Oxfordshire County Council said the changeover of services was due to go ahead on April 1.
It declined to comment on the group’s call for the matter to be referred to the Department for Health.
Previously, Cllr Judith Heathcoat, cabinet member for adult social care, said: “This proposal would enable us to keep the same high standard of care that patients receive now at a lower cost.”
The services currently cost £966,482 and would be reduced to 728,600 a year.