The Jobs, Enterprise and Innovation Minister Richard Bruton says he is concerned about the potential risk to jobs at Liebherr in Co. Kerry.
Mr Bruton says there needs to be careful consideration of the possible implications after the rejection of a pay deal by SIPTU workers at the plant in Killarney.
SIPTU says its committee is currently considering the rejection of Labour Court proposals by its members at the plant.
A secret ballot was held yesterday by the union for the 300 union members at the Killarney container crane factory.
They rejected the recommendation which would have seen the company pay a 2.5% increase in wages, backdated to May 2012, subject to changes in work practices.
The union is now writing to Liebherr to inform them of the outcome of the vote.
SIPTU Organiser Marie Kearney told Radio Kerry that all options are open and they remain available to direct talks.