Postal workers are to stage a one-day stoppage next Wednesday in protest at what they say are breaches of an agreement by management of An Post.
The Communications Workers' Union approved the action at a meeting of its national executive today.
CWU General Secretary Steve Fitzpatrick said the day of protest was the first step in a vigorous campaign of action by the union.
The CWU is in dispute with An Post over the closure of the company's SDS parcel delivery service.
Postal workers are planning to march to Leinster House during Wednesday's strike.
An Post says the CWU is contriving a dispute and ignoring agreed industrial relations procedures.
A statement from the company said the strike was a thoughtless rejection of the interests of pensioners and social welfare recipients who are due payments through the post next week.
