The dispute at An Post looks nearer resolution as the company has agreed to reinstate 92 temporary staff laid off for the past two weeks.
An Post has said it will reinstate those staff early next week, opening the way to the resolution of the dispute.
However, the news was greeted by a rebuke from the Communications Workers' Union (CWU), which represents postal staff.
The unions spokesman Mr Seán McDonagh said: "We are still awaiting confirmation through the proper channels of the LRC that An Post has returned to full compliance with the agreement we all reached yesterday.
"However, if the public announcement by An Post is to be believed, it represents yet a further glaring example of their efforts to deliberately seek to create industrial relations conflicts which are wholly unnecessary," he said.
Last night staff at An Post's Dublin Mails Centre who had been suspended by An Post began returning to work in preparation for a full resumption of services next week.
But a row broke out in private over the company's interpretation of settlement proposals drawn up by the LRC, and the treatment of the 92 temporary staff. Management refused to give guarantees about the future of these staff because there was no work for them, leading to an angry response from the union which threatened to undermine the deal.
Labour Relations Commission chief executive Mr Kieran Mulvey told ireland.comthey were "in contact with both sides to discuss the developing situation".
The two sides are due to begin comprehensive talks next week on the future of the company. They will return to the LRC next week to draw up a schedule for talks on a company recovery plan, to be concluded by mid-May.
Postal services in the areas affected by the dispute, which include Dublin and parts of four other counties, are due to return to normal from Monday.