Talks are set to be held to try to resolve a row over hospital biomedical scientists who say they have been locked out after planning to take industrial action.
Unite said almost 80 staff at Northampton General Hospital face losing up to £6,000 a year under changes to their contracts, as well as having to work more night shifts.
The scientists, who test blood and operate transfusion machinery, were due to take industrial action short of a strike last month but say they were locked out.
Mick Orpin, Unite regional officer, said: "Workers face losing a staggering £6,000 a year and their work- life balance is under threat when up to a million pounds a year is being squandered on agency workers."
Exploratory talks are due to be held at the conciliation service Acas.