An Post has warned that industrial action threatened by the Communications Workers' Union, could have catastrophic consequences for the company.
The union is currently balloting postal staff for industrial action in a row over pay and productivity.
It could trigger an overtime ban disrupting the peak Christmas post season.
The result of that ballot is expected in two to three weeks.
The Minister for Communications, Marine and Natural Resources, Noel Dempsey, said there must be certainty in the very near future about the Christmas post to allow consumers to make arrangements.
He called on all parties involved to come to a conclusion as a matter of urgency.
