The Eircode system is "worse than useless" and serious questions remain about the system, a Sinn Féin spokesman said today.
The party's spokesman on Communications Michael Colreavy said that the system has not helped those it was supposed to benefit.
The Government says that the Eircode system is in its infancy and will take time to develop.
However, Michael Colreavy said that that even emergency services are not using the new post codes.
"There were warnings by several people, including the emergency services - and indeed by courier services and their livelihoods depend on getting parcels to homes quickly - they said that the system is useless to them,"
"The Departments that were supposed to be using it, the Garda Síochána, the ambulance and fire services are not using it, and neither, indeed, are An Post."