Research by the Economic and Social Research Institute claims a new universal social charge could bring in enough revenue to replace PRSI, the health levy and the income levy.
Last year, Minister for Finance Brian Lenihan signalled his intention to combine PRSI and the two levies into a single social charge that would be applied to all income, but at a lower rate.
The ESRI research shows a 7.5% charge could raise enough money to replace all three.
The top rate taxpayers would see their marginal rate fall from 52% to 48.5%.
However, all other income groups would lose out, unless there was a compensating mechanism, such as higher top income tax rates.
The ESRI's research was presented at a conference on budget perspectives this morning.
