Staff at the Centre for Environment, Fisheries and Aquaculture Science (Cefas) will walk out next Wednesday, after complaints that their pay has fallen behind other staff at the Department for Environment, Food and Rural Affairs (Defra) by 10% since the department was established last year.
The workers involved in the dispute belong to the Public and Commercial Services union (PCS) and Prospect.
"It is ludicrous that we have members working at Cefas who are contributing to the same strategic objectives in delivering a service for Defra, but who are being paid substantially less for their contribution," said Geraldine O'Connell, national officer of Prospect.
"Our members wish to send a clear message to management and ministers that staff will not accept being discriminated against on pay."
Beth Lamont, the PCS negotiations officer, said: "There are staff working in personnel, finance and administration who are doing exactly the same work, in some circumstances in the same location, but who are earning up to £3,000 less than their colleagues."
The scientists work in laboratories in Weymouth, Lowestoft and Burnham-on-Crouch in Essex.
