An Post has ignored calls from the Communications Worker's Union and the Labour Party to defer closure of its parcel delivery service (SDS) next February.
The closure of the service will result in the loss of 270 jobs and staff have been given until tomorrow to sign up for redundancy, retirement or redeployment.
An Post chairwoman Ms Margaret McGinley said decision to integrate the service "into core An Post operations" was the correct one.
"The Board has considered issues, raised by the Communication Workers Union (CWU), in relation to the decision taken last July to integrate the SDS business into core An Post operations.
"Following detailed discussion on the matter, the Board concluded that the basis for its decision was sound and that the implementation of the decision must continue in accordance with the timescale set at its July meeting," she added.
An Post claims SDS lost €28 million over the last five years and had no prospect of a turnaround in fortunes.
Members of the CWU protested outside the GPO today, calling for an independent review of the figures used by An Post to justify the closure.
They were joined in their demands by Labour spokesman on communications, Mr Tommy Broughan, who said that conflicting reports on the financial state of the service justified further investigation.
"Minister Dempsey, as the senior representative of the shareholders must now urgently investigate the finances of SDS to clarify the true picture for Dail Eireann," said Mr Broughan. "Pending that investigation, the so-called 're-integration' of SDS into An Post must be halted.
Ms McGinley welcomed the agreement reached by workers and the company - in front of the Labour Relations Commission last Friday - on Christmas mail arrangements.
"I believe that the conclusion of this agreement augurs well for the resolution of the other issues currently in the industrial relations arena, most importantly the Change Programme.
"This programme has been the subject of a process conducted by the LRC since last April and it is vital for the future of the company that it is finalised, through the Labour Court if necessary, without delay."
