The Communications Workers Union has warned of total chaos in the run-up to the key Christmas period, if talks between An Post management and unions at the company fail to reach agreement.
Sean McDonagh said that workers might refuse to work overtime over Christmas, which would result in disruption to mail services.
He was speaking as a six month talks process chaired by the Labour Relations Commission ended shortly before lunch.
It is understood that the company has put a pay offer of 5.35% on the table for collection and delivery staff as part of a comprehensive package involving significant work practice reforms.
The Communications Workers Union executive will meet next week to consider the proposals, and has already begun a consultation process with members.
An Post said that the company had reported unsustainable operational losses last year of €43m.
A spokesperson said it was expected that outstanding issues from the LRC process would be fast-tracked to the Labour Court, and until those hearings were complete, the company would not be commenting further.
Under its survival plan, An Post is seeking 1450 job cuts and significant changes in work practices. It has already pleaded inability to pay the terms of the national wage agreement Sustaining Progress.
