The State's top 50 earners paid less than 5 per cent in taxes, according to the latest analysis of tax records by the Revenue Commissioners released yesterday.
According to the survey, three of the wealthiest Irish paid nothing at all in taxes, while 45 paid between 0 and 5 per cent in 2003, and 17 more paid less than 10 per cent.
Minister for Finance Brian Cowen last night said that curbs he had introduced to the tax code in the 2006 budget will reduce the ability of high earners to cut their tax bills. However, Labour TD, Joan Burton said the figures, which do not count Irish tax exiles such as Denis O'Brien, JP McManus and Dermot Desmond, were "a shocking indictment" of Fianna Fáil's taxation record.
"Fianna Fáil has presided over a tax regime that has allowed super earners to use a range of tax loopholes and avoidance measures to minimise their tax liabilities," she said.
And the problem has not been solved, she said: "As soon as one loophole is closed, these individuals use the army of tax advisers and lawyers that are available to them, to find other ways of avoiding paying their fair share of the taxation burden.
"In addition, our very lax requirements regarding residency status allow many millionaires to minimise their tax liability by claiming to live abroad, when they are in effect still operating virtually full time in this country," said the Labour finance spokeswoman.
Comparing the 2002 and 2003 tax years, the Revenue Commissioners found that the numbers of high-earners who paid less than 30 per cent "remained constant".
"The number of taxpayers with a zero effective rate decreased from 6 to 3. The number of taxpayers with an effective rate of less than 15 per cent increased from 79 to 80," it said.
"Overall, the data do not indicate that there was a significant increase in the use of the various tax reliefs to reduce the effective tax rates of these taxpayers," the commissioners reported.
Changes in last year's budget mean a large number of property tax reliefs are to close next year. Mr Cowen said this will reduce the ability of high earners to offset these reliefs against annual income. "The restriction of relief measures which took effect from the first of January this year will mean that the tax take from the better off will rise and the tax system will be more equitable as a result," he said.
In the biggest change, high earners will pay not less than 20 per cent a year in tax on income sheltered using Department of Finance-approved tax shelters.
Fine Gael TD, Richard Bruton said the average tax bill for the highest earners had fallen by 2 per cent, showing once more how high earners "can manage to entirely avoid paying tax".
The number of high earners paying less than 20 per cent has increased by a third and, on average, each of them is writing off a minimum of €500,000 against their tax bills, he said.