An member of Parliament who introduced anti-smacking legislation in 2007 is appalled that Conservative Party leader Colin Craig has publicly admitted he smacks his daughter.
Former Green MP Sue Bradford says Mr Craig promoted family violence in a RadioLive interview on Monday morning.
In the interview, Mr Craig said he smacks his daughter occasionally, despite the possibility he could be prosecuted.
Ms Bradford said the law reform is changing the culture of violence towards children and Mr Craig is undoing that good work.
Mr Craig said he wants the anti-smacking amendment repealed because it is not working. He says there has been a increase of 30% in notified child-abuse cases since 2008.
As at April last year, the police had prosecuted nine people for smacking since monitoring began in June 2007. All but one were convicted.