Staff at Kerry Group plants in Charleville, County Cork, have voted in favour of industrial action.
SIPTU says its members will carry out a one-day work stoppage next Monday over the refusal of management to attend talks at the Workplace Relations Commission.
The union says the dispute surrounds proposed changes to workers’ terms and conditions of employment.
It says the industrial action is avoidable if management agree to attend the WRC.
SIPTU’s Terry Bryan said: "Our members have voted by a margin of 94% to 6% in favour of taking industrial action as a direct result of a management decision to withdraw from the WRC process.
"This provocative step by management is clearly in breach of the agreed dispute resolution procedures at the company.
"The items that are in dispute include proposed changes to shift patterns and terms, job rotation and appointments."
He said the dispute was due before the WRC on November 28, 2016.
Mr Bryan said: "However, management withdrew from that scheduled hearing and has now refused to attend a conciliation meeting at the WRC.
"The one-day stoppage is avoidable if the company complies with its agreed dispute resolution procedures and attends the proposed WRC meeting."