Two former members of the Commission on Taxation have suggested that reforming or abolishing some of the 131 existing tax breaks could raise more than €2.5bn in the next budget.
They told the Dublin Economic Workshop in Kenmare, Co Kerry, that €11.4bn is lost to the system each year through the tax reliefs.
Earlier, Minister for Social Protection Éamon Ó Cuív said that there will have to be spending cuts at his department in December's budget.
Speaking on RTÉ's The Week in Politics, the minister suggested that the cuts to the welfare budget may not be 'necessarily across the board', but that adjustments would have to be made.
Labour Party Finance Spokesperson Joan Burton said her party did not agree with the Government and Fine Gael 'consensus' that lower and middle income earners should shoulder the burden in the Budget.
Meanwhile, Fr Peter McVerry has called on the Government not to hit the poor, the homeless and the socially excluded in the forthcoming budget.
The Social Justice Campaigner was speaking at an event to mark the International Day for the Eradication of Poverty.
Fr McVerry said that people who did not gain much during the boom are now bearing the brunt of the reduction and closure of services they need.