Baby Neve watches Prime Minister Jacinda Ardern speak on child poverty reduction in Parliament

As Prime Minister Jacinda Ardern stood in Parliament discussing legislation that will impact future governments' approach to child poverty, her baby sat at home watching.

Ms Ardern posted a photo to Instagram of the adorable moment her daughter Neve watched her mum on Parliament Television during the third reading of the Child Poverty Reduction Bill.

"Someone was watching the final vote on the Child Poverty Reduction Bill in Parliament just now," the post reads.

"Very proud to have this Bill finally pass, and with such wide support. Now to get on with it!"

The legislation requires all governments to set and monitor child poverty reduction targets, as well as publish a child-wellbeing strategy in the hopes of encouraging a greater focus on reducing child poverty and creating political accountability.

Three and 10-year targets on child poverty reduction will be required, as will updates in each Budget.

During her speech, Ms Ardern talked about how reducing child poverty had been a big factor in political career so far and she thanked all those that had worked on the issue "over a number of years".

Ms Ardern has previously said her Government's goal was to halve child poverty in ten years, "taking the rate of poverty and hardship among our children to world-leading low levels".

The Bill received bi-partisan support after the Government decided to include several changes favoured by the National Party.

Those include:

  • Reporting annually on one or more 'child poverty related indicators' related to the broader causes and consequences of child poverty
  • Having regard to principles of early intervention and evidence-informed policy when developing the Strategy
  • Setting out how the Government intends to evaluate the effectiveness of policies included in the Strategy

National leader Simon Bridges said in October they were "important changes" that ensured "evidence-based policies" were in place to "improve the lives of our most vulnerable children".

"This is no longer just an initiative of the Labour party... it is also an initiative that has had the support of the National Party. I want to acknowledge that," Ms Ardern said on Tuesday.

"It will have an enduring legacy."

The Children's Commissioner, Andrew Becroft, said the Bill's passing was "an historic cause for celebration".

"It's had to exaggerate the importance of what this could achieve - nothing less than the reversal of 30 years of marginalisation for our poorest children," he said.

"It demonstrates a willingness to change the system in the interests of moving people out of poverty."

However advocacy group Closing the Gap said the legislation only focuses on "process issues" and doesn't get to "the root of the problem".

Spokesperson Peter Malcolm estimates nearly 300,000 children live below the poverty line, and says inequality must be targeted by introducing a living wage, capping CEO salaries and reforming the tax system to include a capital gains tax.

The Child Poverty Monitor released last week showed 100,000 children don't get enough food, leading to increased demand for the Auckland City Mission's Christmas Drive.

The ACT Party voted against the legislation.