Every week 40,000 children turn up at school without breakfast and child poverty in New Zealand is a "national disgrace", Labour says.
Its MPs are citing a report released on Tuesday which says 270,000 children - 25 per cent - are living in poverty.
Social Development spokeswoman Jacinda Ardern says the Children's Commission report demands immediate action from the government.
"It points out that the incidence of child poverty is `unacceptably high'," she said.
"The number of children living in hardship is also up from 15 per cent to 21 per cent - if there's one thing we should be doubly outraged about it is that."
Education spokeswoman Nanaia Mahuta says 40,000 children turning up at school without breakfast is "appalling".
"Teachers often tell me they have to provide breakfast and lunch for their students so they can pay attention in class. It's just not good enough," she said.
"Child poverty is a national disgrace, it's a health issue, an economic issue and a matter of social justice. It is also an education issue."
Ms Mahuta says some parents keep their children out of school because they don't have winter clothing or shoes.
Social Development Minister Paula Bennett says the recession hit low income families hard and the government is working its way out of that.
She has told her officials to work with the Children's Commission so it can have input into the white paper on vulnerable children she is drafting.