Some of An Post's largest customers have strongly criticised the company's performance in relation to bulk mail.

In response to a ComReg-organised consultation process on bulk mail, the State's largest mobile phone company, Vodafone, outlined a range of shortcomings it finds with An Post's service.

Vodafone produces 10 million mail items a year and says that, over the past three years, it has become seriously concerned about several issues. It mentions the significant postal backlogs of Christmas 2002, the industrial action earlier this year and tariff increases.

One of its strongest criticisms relates to international mail. It claims that foreign mail is delivered into Ireland by An Post at a loss because of international agreements An Post has failed to change. It says postal services sending mail into the State can avail of rates 35 per cent below those available to Irish customers of An Post.

Vodafone says this situation "remains the greatest single threat to the viability of the universal service". It says the situation is "discriminatory against postal users in Ireland".

Another major user of the postal system, TICo Group, also raises the issue of the charges for foreign mail as against domestic mail. TICo produces more than 400,000 mail items each week and its customers are in banking, the charity sector, telecoms and the travel trade.

In a submission prepared by TICo managing director Mr Alex Pigot, the company says tariffs between countries should not be discriminatory.

The Irish Missionary Union, which represents 76 religious organisations, said its members were large users of the postal system and were often involved in fund raising by direct mail.

It expresses unhappiness with recent price increases in particular. "Consequent to the unprecedented price rises by An Post in recent years, some of our members are now forced, like other businesses, to use Royal Mail services in Northern Ireland, or private carriers, for their international mail, where they can achieve savings of almost 50 per cent," its submission says.

The Missionaries of the Sacred Heart also wrote to ComReg complaining about the service. "Regrettably, it is our experience that the service quality provided by An Post is in serious decline, particularly during the past 12 months," it says.

ComReg has directed that An Post should provide offices for direct mail in any towns with populations of more than 15,000. A spokesman said this would only add costs to the company, which was already providing an efficient bulk mail service.

He said An Post did not wish to comment on the various submissions made.