Labour leader David Shearer says feeding students at low decile schools would have a positive impact on health, employment and crime statistics in the years to come.
Mr Shearer said on Monday the Labour Party would give free food to children in decile one to three schools if it gets back into power.
He said that would ensure children get the best education possible and put the cost at between $3 million and $18 million.
In response to comments that the money could be better spent on boosting the economy, Mr Shearer said giving food to low decile school children is a faster soloution than creating jobs for their parents.
Education Minister Hekia Parata told Radio New Zealand's Morning Report programme on Monday the Government is already paying for fruit in schools, contributing to charities that provide food to students, and giving more than $62 million a year in food parcels.
However, she said the Government also expects parents to prioritise food over other spending.
Prime Minister John Key said not every school will want every child to be provided with lunch.
Mr Key said fruit is provided in the bulk of low-decile schools, with breakfast programmes often offered and sometimes an emergency lunch.
However, Principals Federation president Paul Drummond says the direction Mr Shearer is taking will please most teachers.