The Government has been called on to expedite measures to protect the livelihoods of Tara Mines workers and the long-term future of the facility, following a meeting with ministers.
It comes as Tara Mines unions and management are set to meet for talks at the Workplace Relations Commission on Tuesday morning.
Boliden, the owner of Tara Mines in Navan, Co Meath, has cited spiralling energy costs and a drop in zinc prices among the reasons for suspending operations at the facility from later in the month, resulting in the temporary lay-off of 650 workers.
Those representing workers say Boliden has yet to produce a satisfactory plan for the future of the plant or what payments may be put in place if the mine does not reopen.
Employment Minister Simon Coveney and Justice Minister Helen McEntee met with trade union representatives on Monday ahead of the temporary closure.
Siptu TEAC division organiser Adrian Kane said the meeting had been called in order to make clear to the Government that measures must be introduced to safeguard the livelihoods of members and ensure the long-term future of Tara Mines.
“It was clear from the meeting that the Government is committed to exploring what measures it can take to provide financial assistance to this essential economic asset," said Mr Kane.
"However, due to EU prohibitions on certain types of state aid, this will be a complex task, and it is extremely unlikely any measures can be in place prior to the scheduled temporary closure of the mine on July 14.
“The union representatives also raised the issue of enhanced social protection measures for our members in the event of a lay-off situation. Currently, Ireland has a social protection system outside of the European mainstream which does not include a payment of a percentage of a worker's previous earnings."
Siptu sector organiser John Regan said Boliden has yet to present to unions with "a satisfactory outline" of what it envisages providing its employees in terms of a retainer and other payments in the event of a lay-off.
"This is a completely unacceptable situation, and does not bode well in terms of where this dispute is heading,” he said.