The Workplace Relations Commission (WRC) is to hold talks next week on the temporary closure of Tara Mines.
SIPTU said it has been invited to a meeting on Tuesday at the WRC to discuss a number of outstanding issues including possible layoff terms and considering factors which could bring the mine back into full operation.
Representatives of the owners of Tara, Boliden, are also expected to attend the talks at the WRC.
Earlier this week the company confirmed it will go ahead with its plans to suspend the operation and temporarily lay off 650 workers in the middle of July.
It said the losses have been driven by several factors including a decline in the price of zinc, high energy prices, general cost inflation and operational challenges.
On Monday, unions are due to meet with Government representatives including Minister for Enterprise, Trade and Employment Simon Coveney.
"Top of the agenda, at these talks, will be what possible actions the Government could take to save the mine from a temporary closure situation," said SIPTU Division Organiser Adrian Kane.
"We will also be seeking commitments in regard to social protection measures to safeguard our members' livelihoods and the local economy," Mr Kane said.
"The Government and the company must be fully aware that our members will not accept moves that will endanger the future of this vital economic resource or the economic wellbeing or their communities."
"We will not be leaving this mine until all outstanding issues are resolved to the satisfaction of our members," Mr Kane said.
