Industrial action which has crippled Ulster postal services over the past week could continue through the Christmas period if no agreement is reached, the Communications Workers Union has warned.
CWU regional secretary, Laurence Houston, warned that if no agreement between the union and Royal Mail could be reached, strikes could continue through the festive season.
"We have not planned that far out and we are absolutely hoping that Government intervention will force the company to reach a resolution," he explained. "If not, we are in a situation where Royal Mail is planning to axe around 40,000 jobs. We can't allow this to happen."
Mr Houston's warning comes as thousands of Ulster postal workers returned to work this morning after taking part in two rounds of UK-wide strikes.
From early this morning disgruntled workers, who walked off the job over a row over pay, jobs and pensions, began the mammoth task of sorting through the backlog of mail.
But their return may be short- lived.
Marathon peace talks at the weekend failed to break the deadlock and the Communications Workers Union has warned a series of rolling strikes will commence next week if no agreement can be reached.
"Further strikes are planned for the 15th," Mr Houston said. " It will be a series of rolling strikes which will be spread out across all functions.
"As we have said before, this is a last resort. We don't want to strike but the company has refused to be reasonable.
"Royal Mail have said they want to reopen negotiations and we are prepared to discuss the issues with them but we are not backing down.
"We are in no doubt that we are going to win this dispute. The future of the postal service depends on it."
A spokesman from Royal Mail said talks between the two parties were ongoing and that the organisation hoped some agreement could be reached before the next scheduled round of industrial action was set to begin.
Further strike action was likely to have a knock-on effect, disrupting businesses throughout the province.
"Royal Mail would like to apologise to customers and would advise people not to post on strike days," the spokesman said. "It will be some time before the backlog will be cleared."