SIPTU has confirmed that up to 70 jobs will be lost with the closure of Drogheda-based manufacturing company Rexxam at the end of this year.
The Japanese-owned company makes circuit boards and has been in the town for 25 years; it was formerly known as Brother Ireland.
Assistant industrial organiser with SIPTU Denis Sheridan confirmed: "We have been told the company will close at the end of December."
The company told the union that 80% of its customers have been lost and it only has sufficient work to remain open until the end of the year.
"We will be meeting the company and starting the process of redundancy talks. We hope the company will enter meaningful discussions with us," Mr Sheridan added.
The news was described as "a devastating blow for the families directly affected," by Sinn Féin councillor Imelda Munster who said the decision came "out of the blue for the workers."
Louth deputy and recently-appointed minister Ged Nash said IDA Ireland has been working with the company "for some time now, conscious of both the fact that the company was almost entirely dependent for its business on one major client in Scotland and the ongoing decline over the last decade or more in circuit board production in Ireland and Western Europe for the global electronics industry."
The minister added: "The difficulties faced by Rexxam are a reminder that the fight to sustain and win new jobs is a continuous one and the challenge to maintain our attractiveness for investment in an increasingly competitive market is a challenge we must take on each day."
Sinn Féin TD for Louth, Gerry Adams, has described the news as 'a devastating blow for these individuals and their families. '
Mr Adams said the factory had "been in Drogheda's Industrial Estate since 1989 and many of those set to lose their jobs are long term members of staff."
Mr Adams added that he would be looking to speak Mr Nash to see if he could intervene to prevent the job losses.