The Unite trade union has expressed outrage at proposals advanced by Tara Mines during talks at the Workplace Relations Commission (WRC) today.
Last week, workers were asked by management to express their interest in a proposed voluntary severance scheme which would see fulltime staff numbers reduce by around 200.
Management at Europe's largest zinc mine are planning to reopen the facility outside Navan in the second quarter of this year.
The mine was placed under care and maintenance last June, with 650 workers temporarily laid off.
In a letter to staff last week, management said that in order to reopen the mine sustainably, "difficult decisions" would need to be made.
Workers were informed that the "most effective and efficient way" of operating at reduced targets would require a workforce of 405 full time equivalent roles.
There are currently approximately 600 full time equivalent roles at the company.
Last week, SIPTU expressed its disappointment over how the company had communicated the information around the severance scheme and said its terms fell well short of what they will be seeking during negotiations.
Unions and management attended talks at the WRC today and will meet again on 22 January.
Following today's meeting, Unite said the terms of the redundancy scheme are significantly worse than what was previously agreed with unions.
Unite said that unless the company withdraws what it termed an unacceptable approach to workers' jobs, terms and conditions, and commits to a firm re-opening date, the Government must intervene to secure the future of the mine.
