Key Points:

Many poor New Zealand children are going to school hungry, but there is no evidence to substantiate a claim the figure is as high as 15,000, Prime Minister Helen Clark says.

Charity KidsCan, which runs a programme to help feed poor children in schools, believes up to 15,000 primary pupils will start the new school year on empty stomachs.

KidsCan secretary Carl Sunderland told the New Zealand Herald said the experience of feeding 3000 children a week, coupled with research by the Poverty Action Group suggested over 10 per cent of the 125,000 primary-age children in the country's poorest schools were malnourished, with hunger inhibiting their ability to learn.

But Miss Clark today said the 15,000 figure was an extrapolated from anecdote and there was no hard evidence to back it up.

She said there were undoubtedly poor children in New Zealand going hungry, but the situation had improved in recent years.

"I don't think there is any evidence to substantiate the figure of 15,000," she said on Newstalk ZB.

"But if the question is are there families on low incomes in New Zealand that have some problems feeding their children, of course there are, but my point is there are fewer of them.

Miss Clark said the Government's Working for Families welfare package was making a big impact on poverty and repairing damage from 1990s welfare policies such as market rents for state houses.

National Party leader John Key announced plans at the weekend for a Food for Schools programme, and cited the school closest to Auckland's so-called "dead-end street", McGehan Close, as the first target.

But Wesley Primary principal Rae Parkin said the school did not need or want the free lunch and breakfast programme.

The Government has denied political interference in the school's decision.

Miss Clark said she understood the school did not want to take part in a National Party political stunt that would have left it with a national profile as a school where parents did not feed their kids.

Ms Parkin told NZPA all she had been expecting was some muesli bars for fund-raising.

"John Key hasn't even visited my school," she said.

The decile one school is near McGechan Close, one of the "mean streets" Mr Key identified in his speech last week when he talked about an "underclass" in New Zealand.

But Mr Key said his offer had been clear, and he had told Ms Parkin there would be media interest.

He said she had changed her attitude during the last 48 hours.

"The only assumption I can make is that there was external influence."

Education Minister Steve Maharey said Mr Key's allegations were disgraceful.

Mr Maharey said the Education Review Office had put in a good report on the school.

It looked after its pupils and had established good relationships with parents.