The Economic and Social Research Institute (ESRI) has called for a review of the value of tax reliefs used to support the pension system.
According to the institute, serious inequities exist within the pension system, including how favourable tax arrangements predominantly benefit higher-income taxpayers.
The ESRI's report, Pensioners' Incomes and Replacement Rates in 2000, found that the public pension system provides pensions for 91 per cent, while the private system provides for just 33 per cent.
The report also found the private pension system provides almost no retirement income for pensioners in the bottom three-fifths of the pensioners' income distribution.
The institute noted the state pays nearly as much in tax incentives for private pensions that it does on state pensions.
Meanwhile, Age Action Ireland said that the Government should be wary of reducing tax breaks on occupational and private pensions especially at a time when only 52 per cent of workers are in occupational schemes.
Green Party spokesman on Finance, Dan Boyle, said that serious questions needed to be asked.
"Inequities and inconsistencies throughout the system mean that large numbers of Irish workers, particularly the lower paid, are not having their future pension provisions properly catered for," Mr Boyle said.
"The Government bears ultimate responsibility for this," he concluded.