The Avonmore Waterford Group has been warned that it could face a serious dispute if it tries to close down one of its main dairy processing plants at Dungarvan.
The plant employs more than 200 people and is the main source of employment in the Co Waterford town.
The Irish workforce of AWG is voting on a voluntary redundancy package negotiated by their unions.
Yesterday, an ATGWU district officer, Mr Tony Mansfield, said the unions had agreed to recommend the package on the strict understanding that all redundancies were voluntary.
"We are prepared to negotiate about the level of production facilities at Dungarvan," Mr Mansfield said.
"But if management refuses to negotiate and closes the plant we will be into a dispute situation. We will fight to save the site for this town," he added.
Mr Mansfield said Dungarvan union representatives had been perturbed when the Tanaiste and Minister for Enterprise, Trade and Employment, Ms Harney, told them on Monday that she understood the Dungarvan plant "would be seriously hit" by restructuring plans at AWG.
"She said there was talk of another project for the site that would create new jobs in the future, but we want to preserve actual jobs and a viable plant that already exists," Mr Mansfield said.
In the short term, the site at Shandon, where there has been a processing plant for almost 90 years, would be converted into a car park.
Mr Mansfield said the unions welcomed Ms Harney's frank and open approach. He only wished the company had been similarly open.
He said the company had failed to consult the unions when drawing up its rationalisation plan. The Dungarvan plant was the most profitable in the group.
Last night, a spokesman for Ms Harney declined to comment on Monday's meeting.
But he did say Ms Harney had urged both sides to agree the restructuring of AWG "on the basis of dialogue and partnership".
A spokesman for AWG said no final decision on the future of any plant would be taken before the restructuring report was completed and submitted to the board. This is likely to be early next week.