Minister for Public Expenditure and Reform Brendan Howlin has said he does not agree with the Fine Gael position on the Universal Social Charge.
Responding to proposals by Fine Gael to further reduce and ultimately abolish the USC, Mr Howlin said the impact of totally abolishing the tax needs to be looked at.
He said someone earning €25,000 would benefit by €750 if the USC were abolished, but someone earning €150,000 would benefit by €16,000.
He added: "If that's the Fine Gael position, it's not one I agree with."
He said the Labour Party is in favour of progressive taxation to fund quality public services.
Earlier, Tánaiste Joan Burton said she was flattered that Fine Gael had adopted a Labour proposal to reduce USC for those on low and middle incomes as a priority.
She said Labour was focused on reducing the tax for those on incomes between €30,000 and €70,000 and also on those up to €100,000.