Former NZ First MP Darroch Ball, who advocates on behalf of victims, has described the Greens as "out of touch" for opposing the registration of child sex offenders.
Nearly 600 child sex offenders will be put back on the national register after MPs rushed through urgent, retrospective changes on Wednesday to the Child Protection (Child Sex Offender Government Agency Registration) Act 2016.
The Supreme Court ruled in 2016 that the law was not clear enough when it came to people who committed an offence before it came into force but were convicted and sentenced after that time. It meant hundreds were removed from the register.
The amendments passed on Wednesday - with support from National and ACT - means the law now applies to all individuals who have committed a child sex offence, regardless of when it happened. It means those people can be monitored by police but the public cannot access it.
The Greens were the only party to oppose the amendments, and Green MP Golriz Ghahraman went further by questioning in Parliament the need for a child sex offender register altogether.
"Children and young people are most often abused, in terms of the types of offending that this piece of legislation encompasses, by those who are very well known to them, in their own homes. They are very rarely abused by strangers," she said.
"These registers have existed and been applied in other jurisdictions for many years. It's a measure that we've taken... It's neither here nor there, I guess we could say, if there's no evidence that it works.
"To persist with it, to lie to ourselves, to lie to victims and the public and say that we're doing something that is essential to protecting children and young people, whilst we weaken the rule of law as a Parliament is, I would say, unacceptable."
Ball, who co-leads the Sensible Sentencing Trust which advocates on behalf of victims of serious violent and sexual crime and homicide, said the Greens are out of touch.
"Ms Ghahraman's comments are alarming but not surprising. The register is about the protection of children, not the protection of the offender, which seems to have been lost on Ms Ghahraman," he told Newshub.
"It is clear that the Greens are more worried about not 'punishing' convicted child sex offenders than they are about wanting to protect and prevent more victims."
Ball said any step taken to protect children from becoming future victims of a convicted child sex offender is one that should be taken.
"To say there is 'very little evidence' that registers work is disingenuous. The fact is there is no evidence that these registers don't work. We need every step and protection we can have to put between these offenders and our children," he said.
"Her comments simply show how out of touch the Greens are with the rest of the country and shows how they clearly have no understanding of the effects these crimes have on the victims and the community."
National MP Simeon Brown described the Greens' opposition to the amendments as "outrageous" and accused them of putting "politics ahead of the safety of our children".
Ghahraman said her remarks reflect former Attorney-General Chris Finlayson's 2017 report on the legislation, which raised concerns about whether the retroactive aspect of the proposed amendments was lawful.
"I consider there is no doubt the purpose of the Bill, and the principal Act, is a sufficiently important objective to warrant some intrusion into the rights and freedoms affirmed in the Bill of Rights Act," Finlayson wrote.
"On balance, however, I consider the degree to which the Bill and the principal Act intrude on the right not to be subjected to retrospective punishment outweighs the importance of the Bill's objective."
Finlayson also questioned the effectiveness of child sex offender registers, but determined that the objective to protect children outweighed the lack of evidence.
"The scarcity of evidence that child protection offender registers deliver significant benefits in terms of improved public safety has been noted in numerous studies," he wrote.
"The lack of evidence for improved public safety should, however, be weighed against the severe harm caused to the victims of sexual offences against children... I therefore consider there is a sufficient rational connection between the limitation and the objective."
ACT MP Nicole McKee said while her party does not agree with retroactive laws, they were "not prepared to trade off our children's safety and their futures" by opposing the amendments.
"These are clear issues where we have to decide what is more important in regard to this law: our children or allowing an error in law to continue? We choose our children."