Hundreds of NHS workers are to vote on strike action over government plans to privatise part of the health service.
Staff are angry at the proposed transfer of NHS Logistics to haulage firm DHL, the Unison union has warned.
NHS Logistics is a not-for-profit organisation supplying hospitals, GP surgeries and patients with food and equipment. It employs about 1,400 staff across five depots in England and makes 1,200 deliveries each day.
Ministers said the plan to transfer the group to DHL could help save money which could then be invested in patient care.
But Karen Jennings, head of health at Unison, said the government's decision to privatise was driven by "pure dogma" and an "obsession with market testing".
"DHL will be rubbing its hands together at the thought of getting hold of such a successful business operation, with a lucrative turnover of around £777m a year," she said.
Health minister Andy Burnham said the government was looking at staff concerns before making a final decision.
"We recognise the important role that NHS Logistics plays and the good job that staff are doing in helping the NHS run on a daily basis," he said.