The prospect of a serious disruption to the State's postal services next week looked increasingly likely today after talks to avert planned strike action ended without a breakthrough.
An Post management resumed talks this morning with Communications Workers Union (CWU) in a bid to settle the dispute over pay.
But An Post later confirmed the talks had been adjourned indefinitely, with no immediate plans for a resumption.
This follows an announcement last night by the CWU that its workers would to go on strike from midnight on Monday.
The union said the action will consist of a nationwide ban on overtime, in addition to an all-out strike at the GPO in Dublin and other "selected locations" throughout the country.
While mail deliveries will be disrupted, the CWU pledged that social welfare recipients would not be affected by the dispute.
CWU National Officer Sean McDonagh today blamed the stand-off on the company's "intransigence".
A spokeswoman for An Post said the company was disappointed at the breakdown in talks but stressed changes in work practices must be brought in before increased wages can be paid.
The company also warned of a serious and immediate risk to postal services, urging all customers not to send mail until further notice.
The strike is over the company's failure to pay the full terms of Sustaining Progress to the CWU's 8,500 members.
An Post accepted a Labour Court recommendation in July - drafted by a technical group including industrial relations troubleshooter Phil Flynn - that the increases be paid provided postal workers agreed to a range of work practice changes.
The CWU says the two issues should not be linked. It says members are entitled to the cost-of-living increases agreed under Sustaining Progress without having to change work practices.
Last night the CWU said An Post had "squandered" the opportunity to resolve the issue prior to the strike.
But An Post condemned the union's decision to go ahead with the action while talks with the National Implementation Body (NIB) were ongoing at Government Buildings.
A spokeswoman said: "Because the system is so dependent on overtime, and that is why we have been trying to change the system for so long, it will cause major disruption nationally to all mail services to all mail services and that is what we are advising customers".
"It is astonishing that they would announce this but we would not be surprised by anything the union does," she added.
However, CWU general secretary Steve Fitzpatrick, who left the talks last night to announce details of the industrial action, said little progress was being made.
"I don't want to mislead anybody. I didn't see any indication that we were doing anything other than exploring possibilities," he said.