Nurses at Derby's hospitals are to be balloted for strike action over a cost-cutting programme.
The trust which runs the city's main hospitals wants to downgrade some posts as part of restructuring. It said it needed to make cuts totalling £55m.
Despite the conciliation service ACAS being brought in, talks between the hospital and unions have stalled.
The Royal College of Nursing union (RCN) met with members on Tuesday night and made the decision to ballot nurses.
Some nurses claim they could be up to £7,000 worse off over two years if they are forced to take a lower grade job.
Jane Slatcher, regional officer from the Royal College of Nursing, said: "Our members are coming forward saying that they have thousands to lose in their pay packets.
"We also have professional concerns. We are a trade union as well as a professional body and we're here to champion the voice of nursing and defend the nursing service.
"We want to seek reassurances about the quality of care that patients are going to continue to receive if these changes go ahead."
Tony Riley, Derby Hospitals' NHS Trust Director of Human Resources, said he was hopeful a resolution could be found.
"We wanted to have as few redundancies as possible and protect as many staff as possible from having their pay damaged too much by this programme," he said.