Element Six workers in Shannon are to hold a ballot on official industrial action over the next few days.
The decision was made following a meeting of union and non-union workers at the plant in response to a plan that could save 160 manufacturing jobs at the plant.
Element Six, formerly known as De Beers Industrial Diamonds, had earlier announced it was ending manufacturing in Shannon with the loss of 370 jobs.
A joint statement by SIPTU and the TEEU stated that they have decided to ballot workers for industrial action to 'protect their jobs and secure better redundancy terms' for workers.
However, both unions said they will 'continue to explore all avenues to resolve the current dispute prior to taking industrial action'.
The company said the plan to save 160 of the 370 jobs would involve comprehensive changes to work practices and increases in productivity.
SIPTU has said its members are angry that a better redundancy package has not been offered by the company.
It also said it does not believe that the jobs proposed in the plan are for the long-term.
TEEU Regional Secretary Pat Keane said: 'We are all committed to doing everything possible to keep these highly skilled jobs in Shannon. The midwest cannot afford to lose more jobs in manufacturing.'
Management at Element Six have invited unions to talks on the future of the company on Wednesday this week.
In a statement issued this evening, Element Six General Manager Ken Sullivan said the issue was whether an agreement could be reached to keep a sustainable business at the plant and said he encouraged everyone to work together to save jobs.
