Members of the Veterinary Officers Association (VOA) have voted to emphatically reject the terms of the Lansdowne Road Agreement.
A total of 92% of members who voted were against the new pay deal.
SIPTU, the Irish Nurses and Midwives Association and the Irish National Teachers Organisation have all voted in favour of the deal.
It would see public sector workers receive a pay increase of €2,000 over the next two years.
VOA president Mary Courtney said: "The result of the ballot of VOA members sends out a very simple, stark message.
"The Government’s pay proposals are both unfair and inequitable. The VOA approached the pay talks with a not unreasonable expectation of being treated fairly.
"Our members experienced a disproportionate reduction in their incomes during the financial emergency but continued to work diligently and professionally to facilitate the expansion of agricultural production and exports in Ireland, thereby significantly contributing to the current national economic recovery.
"The ongoing discrimination and division between public service workers working at different grades continues a dangerous principle being progressed by Government.
"This is particularly abhorrent to VOA members.
"VOA rejected the Lansdowne Road Agreement because its implementation would continue up to 2018 the severe pay cuts suffered by our members.
"This is in the context of a 30% reduction in numbers of staff in the State Veterinary Service and much increased workload for our members due to the continuing expansion of the Agrifood industry and the growth in Certification and official controls required.
"Our members continue to take on new work, as is required in such a dynamic and expanding industry, and despite reductions in support staff, our members discharge their duties with professionalism on a day-to-day basis, while being charged with some of the most important work in the State including maintaining Ireland’s safe food reputation.
"It is deeply disappointing that the Government has shown such disregard for our members in the pay talks, while expecting continued delivery of our wide ranging duties in an environment of critical staff shortages."