SR Technics is due to implement a first wave of mass lay-offs today as part of its plan to wind down its aircraft maintenance operation at Dublin Airport.
The company is set to let 600 employees go today, with almost the same number due to be made redundant between now and August.
All staff have been asked to come into work as normal as it is still unclear who is being laid off today and who is being kept on until the plant is fully shut down.
The workers are seeking one last meeting with management following the company's decision to reject Labour Court recommendations to increase redundancy payments and fund a shortfall in the employees' pension fund.