The Government has confirmed it will repeal the law that penalises solo mothers who refuse to name the father of their child, drawing criticism from the opposition.
The law was introduced so that fathers could be traced and made to pay child support.
Mothers who refuse to name a father can have their benefit payments reduced.
Social Development Minister Carmel Sepuloni told RNZ there was no evidence the law was achieving its purpose.
"What it has done is have a negative financial impact on the parent who - more often than not - was the woman raising the children," she said.
National Party leader Bill English says the Government's move will almost certainly mean there'll be fewer fathers supporting children in the way they should be.
Mr English says the former government thought the sanction was right.
"It's been in place for quite some time and it fits in with the notion around child support that the absent parent, generally a father, has responsibilities," he said.
"The system can't enforce those responsibilities if it doesn't know who they are. So with the removal of that obligation it's almost certain there'll be fewer fathers supporting the children in the way they should be."
Former social development minister Paula Bennett, who introduced the law imposing the penaties, says there are exemptions for women who have valid reasons for refusing to name fathers.
"If they couldn't name the father they do not get penalised. And there's actually exceptions around domestic violence and rape and things where there are valid reasons for a woman not to name a father. And in those there were clear exemptions," Ms Bennett told reporters.
"It's quite a big thing to be dropping it," she said.
"Now there will be a lot of pressure not to name the father so he doesn't have any responsibilities."