The answer to the achievement gap between children in lower and higher decile primary schools lies in fixing the problems that lead to inequality, say Opposition parties.
Research has revealed an average two year achievement gap, shown in average scores for children in decile one, two and three schools, and those of children in deciles eight, nine and 10 as measured by the National Monitoring Study of Student Achievement.
The Ministry of Education acknowledged it had more work to do, but said the government was making a number of changes to the education system.
However, opposition parties say the answer doesn't lie with what happens in schools, but dealing with issues such as low wages, poor housing and unemployment which lead to inequality.
Labour Party education spokesperson Chris Hipkins said the achievement gap pointed to a growth in inequality.
"What happens outside the classroom has a big impact on what happens inside the classroom.
"So the fact that we have hundreds of thousands of kids in New Zealand living below the poverty line, that's something we need to take seriously and deal with."
New Zealand First's Tracey Martin said the struggle for a lot of low-decile school children started before they turned five.
"Every single family needs to have support and it needs to be early on for every single child. But we can only do that if we actually know the child and if we know the family," she said.
"We've got to start personalising our support."
Green Party education spokesperson Catherine Delahunty said schools could not make a difference on their own and a community approach was needed.
"Where you actually build relationships with the community and make sure that the school has all kinds of social services and activities based there, and becomes a genuine resource for a community that's struggling."
ACT leader David Seymour said the education system needed an overhaul, but charter schools were a great way to help children who were previously finding it difficult.
"[It's] what happens when you actually say to social entrepreneurs, 'we in Wellington do not have all the ideas, you know more about the kids in your community than we do,'" he said.
"I think that giving educators greater freedom to innovate is one of the most powerful things we can do to deliver on the promise of New Zealand that no matter who you are or where you're from, you get an equal shot at decent education."