Meat inspectors at the Food Standards Agency (FSA) are to stage two four-hour strikes next week in a row over pay.
Members of Unison in England, Wales and Scotland will walk out from 6.30am on Tuesday and Wednesday.
The move follows a ballot earlier this month, which saw an overwhelming vote for strike action over an imposed pay offer of 0.75%.
Unison has urged the FSA to resolve the pay dispute through independent conciliation.
General secretary Dave Prentis said: "Staff in slaughterhouses work in some of the most dirty, difficult and stressful conditions, surrounded by blood and faeces, to keep the public safe from contaminated meat.
"It is only fair that our members receive a pay increase that is at least in line with inflation. They should be recognised for the vital role they play in safeguarding the human food chain against harmful and repulsive dirt and diseases.
"It is not too late for the FSA to avoid the prospect of a strike that may well clear supermarket shelves and butchers' shops of meat in the barbecue season."
The union is seeking an above inflation pay increase it says would begin to make up some of the 15% that has been lost from the pay of FSA staff since the coalition Government came to power.
A spokesman from the Food Standards Agency said: "The FSA is disappointed that Unison has decided to call industrial action next week, at a time when Unison has said it is committed to ongoing talks with us. We are continuing to hold discussions with Unison, but in the event that the planned strike action goes ahead, we would not expect there to be an effect on meat supplies to shops and supermarkets."