UPDATED 5.38pm: Single parents aren't the main reason why we have children living in poverty says an academic.

LISTEN ABOVE: Susan St John, spokesperson of Child Poverty Action Group, talks to Larry Williams

A Family First report released today from the last census shows just 28 percent of families have single parents, but 51 percent of total children living in poverty are in solo parent homes.

Child Poverty Action Group spokesperson and Associate Professor of Economics at Auckland's Business School Susan St John told Larry Williams to base the reason solely on family structure is wrong.

She said it's easy to point to the fact that sole parents are poorer because of a single income, but it's not the main reason and we should be looking at how to support them instead.

She said there's an awful lot wrong with policy, employment and housing which are the dominant reasons why we have child poverty.

She said the authors of the report have done well to make it look like the main reason is the family structure.

Family Centre policy advisor Charles Waldergrave said countries like New Zealand are experiencing child poverty for a number of reasons.

"The cause of that is less income and less equality across society."

"I think it's got very little to do with whether people are married, cohabiting or sole-parent."

Report author and welfare commentator Lindsay Mitchell said it's time for family structure to be included in the child poverty conversation.

She argues unemployment, high housing rental costs, low wages and insufficient benefits are spoken about at length, but very little about family structure.

The Family First report found 51 per cent of children in poverty live in single parent families, but just 28 per cent of families have single parents.

Mitchell said the figures make for sobering reading.

"Sole parent families are unfortunately the poorest families in New Zealand, so obviously the more sole parent families the country has, the higher the rate of child poverty will be."

However, Child Poverty Action group social security spokesman Mike O'Brien said there are number of problems with the report.

"There are as many children living below the poverty line in two-parent households as there are in sole-parent families."

Mike O'Brien said the issue is about how much money the parent is making to support the family, not how many parents there are.