An Post came under fire tonight for allowing Fianna Fáil exclusive use of its mail-franking service for the entire month of March.
The move cost Fianna Fáil €9,500.
It means that until the end of the month, all mail posted in the State going through automated post centres - about 70 per cent of the total letters and packages will carry the name of the party, including that delivered to all of Fianna Fail's rivals in the imminent election.
An Post makes the franking service available to any company or organisation as an advertising facility.
Fianna Fáil made an approach before Christmas, and is understood to have taken an option for the next two months.
A spokesman for the postal company said: "The service is available to anyone who wants to buy it, and in this case, Fianna Fáil were the first into the breach."
But tonight An Post's decision to accept the party advert was condemned by Fine Gael.
Public enterprise spokesman Mr Jim Higgins said "I have no problem with An Post making this service available for charitable purposes or public service notices.
"But for a state-owned monopoly to allow a political party to use this service for party political branding is entirely inappropriate.
"This is a clear abuse of private property. A letter is the personal private property of the individual who sends it, and for An Post to allow a political party to print its propaganda on the envelope is an interference with that person's right of free association and party allegiance of their own choice."
Phone-in radio programmes on RTE also reported that they had received complaints about the An Post - Fianna Fáil agreement.
PA