The Irish Postmasters Union will hold a meeting of its 600 members this weekend to discuss possible responses to its grievances with An Post over pay and conditions.
General secretary of the union Mr John Kane said the meeting in Portlaoise was the result of a long series of talks with An Post.
He warned the postal service "could be threatened" if more resources were not made available. He said Ireland was a difficult place in which to provide a postal service because of the low density of population.
He said postmasters had been "long suffering" and should not be expected to "prop up a system that is not properly resourced and at rates of pay that are wholly unrealistic in today’s terms".
The union is also concerned at the planned deregulation of An Post and what they call the delays in decisions on price increases.
"Unless some radical and positive action is forthcoming and very quickly there is a real possibility that many of our members could simply opt out," Mr Kane said.