Leader of New Zealand's Conservative Party Colin Craig brands the nation's women the "most promiscuous young in the world"

Key was responding to claims by Conservative Party leader Colin Craig, who has rejected the free contraception plan based on New Zealand having the “most promiscuous young women in the world”.

The contraception will be offered to women on benefits as part of a $287.5 million budget package for the government’s welfare reforms.

Craig rejected the notion of taxpayers forking out for the lifestyle of loose women.

"Until we get back to the principles of personal responsibility and paying our own way, we will not stop the encroachment and continuing cost of a welfare state which we simply cannot afford even now," Mr Craig told Morning Report.

"Why should, say, a 70-year-old who's had one partner all their life be paying for a young woman to sleep around?

“We are the country with the most promiscuous young women in

the world. This does nothing to help us at all."

Key responded by insisting free contraception would help the government “provide support to young vulnerable women, give them a voluntary option, to employ a doctor to give them advice and support in that area.”

Craig’s comments have sparked fury among community groups.

Maori co-leader Tariana Turia said it was outrageous for anyone to talk about promiscuity of New Zealand women when they probably knew nothing about anywhere else in the world.

"We do try to operate on evidence and we don't lie in the bedrooms of other people."