The Government was today criticised for widening the gap between one-income and two-income married couples through tax individualisation.
As a result of Budget 2007, one-income married couples with children will now pay up to €6,240 more in tax each year than two-income married couples on the same income, according to a report from the Iona Institute.
The report, entitled Tax Individualisation: Time for a Critical Treatment, claims the gap has now more than doubled since tax individualisation was announced by the-then minister for finance Charlie McCreevy in 1999.
It condemns individualisation as a form of "social engineering" aimed at forcing as many women as possible into the workforce regardless of their own individual preference.
It also says the State should not favour paid employment over work in the home or vice versa, insisting "one-income married couples and two-income married couples should be treated on the same basis for tax purposes".
In a foreword to the report, Labour finance spokeswoman Joan Burton said: "The policy of individualisation has led to dramatic transfers from families with children to two-income households, many without dependents."
Ms Burton said: "The consequence of individualisation is to introduce a significant and growing bias against families with children where one spouse chooses to stay at home and care for children."