The Revenue Commissioners have acknowledged that staffing levels are below strength in some areas and say this is due to difficulties filling entry grade positions.

A spokesman for the Revenue, responding to a demand from the Impact trade union for an additional 170 staff to cope with what it says is a huge increase in work, said the main problem was in getting new staff. This was a problem being experienced across the civil service, he added.

Impact, which represents employees at the Revenue Commissioners, claims the number of Revenue staff dealing directly with tax assessment and enforcement has fallen by more than 10 per cent in the past 12 years despite the huge growth in the number of tax returns.

"Taxes staff want to provide a fair and efficient service to business and the public. If the Revenue Commissioners share that commitment, they must recognise that massive increases in Exchequer returns necessitate increases in staff numbers," said Impact official Ms Marie Levis.

"Ireland is now a modern and growing European economy and we need to develop a modern and responsive service to cope with the new economic reality," she said. The Revenue spokesman acknowledged that staffing "in some areas" is below strength but said staffing in the audit and investigation areas was generally in line with the authorised numbers.

He said the Minister for Finance, Mr McCreevy, had recently approved a request for 37 additional staff to allow for increased audit activity in financial institutions and large companies, as well as in specific investigations. These positions will be filled by way of promotions, after which replacement of promoted staff could be a difficulty.

The number of Revenue employees dealing with tax assessment and enforcement has fallen from 2,950 in 1987 to 2,640 last year, according to Impact. At the same time, the number of PAYE employee records has risen by over 60 per cent and corporation tax returns have increased by around 300 per cent.