Talks in relation to public sector cuts under are to get underway next Monday.
The cuts are to be negotiated under an extension to the existing Croke Park Agreement and will be aimed at saving the Government a further €1bn.
In a letter to Impact trade union members, general secretary Shay Cody, has warned employees that the talks are expected to be the most difficult yet.
The Government has said it wants to see savings of €300m for 2013.