Discussions between unions and management on reopening Tara Mines in Co Meath have been put on hold.
It is understood staff were told in an update from the company that the negotiations have stalled and that the sides have reached an impasse.
Management said that the position currently being adopted by the group of unions at Tara Mines will not allow for a sustainable reopening.
SIPTU said unions have been told that the mine would remain in "care and maintenance" with no agreement on the resumption of full operation.
"Union negotiators were surprised at this sudden announcement as the talks had seemed to be making headway about the resumption of activities at the mine," said SIPTU Transport, Energy Aviation and Construction Divisional Organiser Adrian Kane.
"The talks came to an abrupt halt when management read out a statement saying that the mine will remain in a ‘care and maintenance’ status with no date for the full resumption of its operations," Mr Kane said.
The group of unions has accused the company of reneging on its commitments regarding the protection of the existing terms and conditions of its employees and said it remains committed to achieving a fair agreement on the resumption of operations at the facility.
Tara Mines closed temporarily in July last year resulting in the laying off of 650 workers.
The parent company, Boliden, said it took the decision due to unsustainable losses and cited factors including a decline in the price of zinc, inflation and energy costs.
