An Post has warned customers to expect delays in mail deliveries over the next few days because of tomorrow's one-day postal strike.
A spokesperson reiterated the company's view that the strike was unnecessary and in clear breach of procedures.
An Post said it would damage the company by undermining public confidence in the service.
The Communication Workers' Union has alleged that the company is in breach of the national wage agreement, Sustaining Progress, by not paying its scheduled wage increases.
It also opposes the closure of An Post's parcel delivery service, SDS.
Meanwhile, a formula has been agreed which it is hoped will resolve a row which has disrupted postal services in Galway city and county.
Traffic disruption
Traffic in Dublin is expected to be disrupted tomorrow as postal workers plan a march through the city as part of their strike.
Around 2,000 members of the CWU are expected to assemble at the Garden of Remembrance in Parnell Square at around midday.
They will then march down O'Connell Street past the General Post Office to the Dáil.
A rally will be held outside Leinster House with speakers from politics and the trade union movement.
CWU General Secretary Steve Fitzpatrick said they were trying to bring their message to Government because they had tried everything else without success.
He said this was a last attempt to get people to intervene and deal with the issues in a proper manner.
The CWU executive will meet on Thursday after the strike to decide its next move.
