Workers at Dairygold in North Cork have voted in favour of industrial action at the company.
The decision follows three-day Ballot of SIPTU members who claim that some employees have been forced out of work as part of a redundancy programme.
The Union has said the company hasn't adhered to proper industrial relations procedures and changes.
Dairygold has written to members of staff advising them that the changes are in the best interests of the company.