A hospital under threat of closure because a health authority needs to save money has stopped taking patients.
The Bartlett Hospital in Felixstowe blamed the move on staff shortages.
But campaigners fighting to save the hospital fear it has already been closed in all but name because it has stopped admitting any new patients.
A consultation is under way into the provision of Suffolk's health services. Patients are now being treated at Ipswich Hospital.
Health managers said it would be clinically unsafe to send patients to the Bartlett at the moment because of a shortage of staff.
They added that the current situation is not permanent.