A row between An Post and its biggest union which threatens to disrupt Christmas mail deliveries intensified yesterday.

An attempt by the company to have the issue referred immediately to the Labour Relations Commission (LRC) was rejected by the Communications Workers' Union (CWU).

In a letter to the company last night, the union accused management of misrepresenting its position.

The company had written to the LRC's deputy director of conciliation, Mr Tom Pomphrett, on Tuesday, informing him that the sides were in dispute over Christmas delivery arrangements.

It asked Mr Pomphrett to hold an "urgent conciliation conference" at the earliest possible time.

The CWU, however, rejected the company's claim that the sides had reached a stalemate on the issue and said discussions had been continuing.

In its letter to An Post last night, it sought clarification on a number of issues before it could decide whether to have the matter referred to the LRC or the Labour Court.

Mr Seán McDonagh, national officer, said the union had no difficulty going to the LRC "when the procedures have been exhausted".

In a separate development yesterday, a survey from the European Consumer Centre (ECC) suggested that An Post's SDS parcel service, which is to close shortly, is the most expensive in Europe .

The European consumer watchdog sent 260 parcels across Europe by priority and standard postage. It found that the most expensive priority parcel was sent from Ireland at a cost of €34.