The Children's Commissioner says he's disappointed child poverty statistics have remained stagnant as children continue to grow up in deprived households.

Commissioner Andrew Becroft says information the latest Household Income Report shows one in five Kiwi kids lived in a house without access to food, while many beneficiaries were currently spending half their income on rent alone.

In releasing its annual Child Poverty Monitor report today, Becroft says he is "concerned and frustrated" not to have information usually supplied by The Ministry of Social Development (MSD).

Speaking with Mike Hosking, Becroft said around 80,000 kids are suffering material hardship.

"We are talking about kids without shoes going to school, without a raincoat, without good, regular meals of meat, fish, fresh vegetables, families that can't pay urgent bills of $500, it's real, it's tangible and it's not really open to interpretation."

The Ministry decided not to publish its latest figures, saying there appeared to have been unusually low response rates by low-income households with children which skewed the results.

He said it is frustrating that they don't have the correct numbers.

"We don't have the statistics. There has been some sampling or statistical errors which are frustrating [but] we are told that there is a survey in the field now of 20,000 households not 6000 and we will know by mid next year what should be a turning of the tide."

The Children's Commissioner said they do, however, know a lot of kids are struggling. 

"We could fill Eden Park twice over with the number of kids who are doing it tough in New Zealand. It's about 100,000 children."

"If you look at the big areas of measurement, health, housing, educational achievement, access to food, they all paint the same story that that 10 per cent that core group are doing it tough."

"That said, 70 per cent of our kids are doing well but the fact that there are such variations and such a width of disadvantage in my view isn't acceptable in a country like New Zealand." 

Andrew Becroft was buoyed that a new bill - the Child Poverty Reduction Bill - was about to pass its third reading in parliament, an effort he praises both National and Labour for both supporting.

"That was a game changer ... having a cross-party accord is historic and the bill is about to be passed any day now and it will be all systems go and I will be watching very closely."

He said a key way to tackle child poverty would be to see benefits - which go to parents with children - increased annually, rather than the current sporadic nature of when a Government sees fit.

"The evidence is, the increase in benefits invariably go to children. I mean the stereotypical put down is that more money into the hands of families invariably means more on alcohol or gambling or cigarettes. But no, the evidence is that it usually is spent by parents who really are concerned about their children."

Becroft said overall he was "optimistic" about changing the statistics.

"I'm deeply concerned about the situation currently. It hasn't got worse but we could do much better and I'm pretty sure we will."