The Taoiseach Enda Kenny is defending the tax cuts in yesterday's Budget.
It follows claims from Fianna Fáil that the changes were unfair and discriminate against low-paid workers.
Under the tax cuts, someone on €17,000 a year gains about €170, while someone on €70,000 or more will gain more than €700.
However, Mr Kenny told Fianna Fáil in the Dáil that the Coalition has started a three-year approach to reducing taxes for everyone.
He said: "Now that's very different to the 52% tax burden that was imposed by your own government which made this country uncompetitive, unattractive and not fair in the sense of the proportion of tax that people had to pay."
The Finance Minister Michael Noonan has said the Opposition has "no credibility" over claims that the water charge cancels out any gains for families in the Budget.
Sinn Féin says income tax cuts are "pathetically inadequate" in comparison to the added burden of the water levy next year, while Fianna Fáil says low and middle income families do not benefit nearly as much as the top earners.
Public Expenditure Minister Brendan Howlin says the opposition are "patently wrong", and his colleague Mr Noonan says their numbers do not add up.
Mr Noonan said: "The tax reliefs in the Budget are worth €1,200 for them, the average water charge is between €240 and €280.
"Sinn Féin miscalculated their policy in terms of water, they said they would abolish it (the ater charge) completely, but hold Irish Water in place.
"Now, once they hold Irish Water in place, everything goes on the balance sheet. They are between €500m and €600m short and the Opposition have no credibility on this issue."