The union says that up to 1,000 meat inspectors are being asked to take action after employers refused to pay last year's agreed pay award unless workers accept cuts to overtime payments and changes in their terms and conditions.
UNISON national officer Simon Watson said: "The employers must give staff the agreed pay rise with no strings attached." He warned that if strike action goes ahead, it will severely affect deliveries of meat in the run-up to Christmas, costing supermarkets and meat producers millions of pounds.
Unison claims that Meat Hygiene Service (MHS) workers have not received a pay rise since August 2006 and that the MHS has refused to pay the 2007 award while negotiations are continuing on proposals for new terms and conditions.
A consultative vote has already seen 83% of members questioned in favour of strike action and 94% in favour of action short of a strike in a 70% turn-out.
MHS chief executive Steve McGrath has reassured the industry that his organisation has "contingency plans in place" to minimise disruption should the strike take place. He insisted that the MHS is doing its best to avoid action and said the organisation "remains committed to securing a negotiated settlement."
The UNISON ballot closes on 21 November.