One Fine Gael Senator says no political party would support a tax on Child Benefit.
Mary Seery-Kearney was speaking amid a proposal from IBEC that Child Benefit should be taxed and the savings ringfenced to boost early years services.
It recommends the benefit is only taxed for higher income families, but kept at the same rate for those on lower incomes.
Child Benefit is a monthly payment of €140 to support parents and guardians, and is not taxable.
But Senator Kearney told The Pat Kenny Show this would never work.
"I'm quite aghast at it, to be honest.
"Child Benefit itself it's a universal support that's paid for all of the children in the State, regardless of their family circumstances.
"But it is predominantly paid to mothers, and my own experience of it... I'm a mother of a surrogate-born child, and that's a whole other days campaign.
"The Social Protection insisted that it got paid to me - and that gave me an insight into their insight, which is 'pay it to mothers'.
"And since then I speak to Dad's who are same-sex couples, whose child is born by surrogacy, and they find it very difficult to get child benefit."
And she says a suggestion to tax it is completely wrong.
"To be honest I think it's tone-deaf to the lived experience of women, and women who are receiving this benefit for the benefit of the child.
"It ignores that fact that in many families money is power, and whoever is earning the money has the power and control.
"And we see that in a lot of domestic violence instances.
"So at least this is something for the mother to spend on her children.
"So to be honest I think it's a very discriminatory attack, and that it would suit them better to confine the scope of their employers support for flexible working arrangements, remote working arrangements, promoting maternity being paid to women and making the workplace a better place for women".
'When do you do the cut off?'
Asked if only higher earning families should have the benefit taxed, she says it would be near-impossible to draw the line.
"The small cohort who don't really need this are a small cohort.
"The vast majority of working couples and working families do need it - so when do you do the cut off?
"When the most expensive childcare place is the baby places and the early years/the toddler places.
"So what are IBEC saying, where do you decide there is no need if childcare is being supplemented by Child Benefit?".
And she says no political party would support this measure: "They won't, absolutely not - and morally neither should they.
"It is reasonable that every child in the State gets a benefit.
"In the vast array of supports for supplementing childcare and helping working families in their childcare supports, Child Benefit should be extremely low on the list of targets for any political party".