Rye Valley Foods in Co Monaghan has been served with strike notice by workers in the Technical Engineering and Electrical Union (TEEU).
The action came after management told workers to take a week's annual leave next week or face a week's lay-off.
According to the TEEU regional secretary, Arthur Hall, the company had not engaged in talks with the union on a decision to close the plant for a week.
Mr Hall said: "What we are witnessing here is a company which is part of one of the most profitable Irish multinationals asking its workforce to take the hit for decisions by management which led to over production.
"Members who decide not to take a week's holidays have been asked not to sign on for the week, as it would draw attention to the company's difficulties. Quite apart from the fact that it will suit very few workers to take a week's break at such short notice, a very high proportion of them are migrants who are being put in a particularly difficult position," Mr Hall added.
Last Friday TEEU members decided unanimously to ballot for industrial action and strike notice has been served for next Monday, June 6th.
Siptu, which represents other workers at the plant, is in discussions with the company.
Based at Carrickmacross, Rye Valley Foods makes pre-packed meals for supermarkets. It employs 700 people and is part of the Kerry Group.