Politicians have the chance to undo 30 years of failing to put children first, an impassioned Children's Commissioner Judge Andrew Becroft says.
The current state of things is dire, he told politicians on both sides of Parliament at Select Committee on Wednesday.
"When you look at the statistics, the numbers on youth suicide, very high on domestic violence, child abuse, how else could it be phrased other than being dire?"
Mr Becroft said 10 percent of children in New Zealand are probably worse-off than in any other Western country in the world.
"Thirty years ago we dropped a ball as a country," he said.
"We dropped the ball in the sense of putting children first."
Jacinda Ardern's Child Poverty Reduction Bill will require governments to set three and 10-year targets on child poverty, with updates provided with each Budget.
Mr Becroft's submission on the Bill was a plea to the Government and Opposition to "transcend petty squabbles" and work together to create legislation that would not be undone by future governments.
"Successive governments for years have at least dropped the ball," he said.
"Recently both parties seem to be getting the clear message."
He said the previous National Government paved the way for Ms Ardern's legislation with its better public service targets and social investment strategy.
Under the new legislation, Mr Becroft said the lives of children would improve materially.
"It's going to mean kids won't go to school without shoes, without a raincoat. They'll be fed, they won't rely on schools to provide lunches and breakfast. They will be able to get to the dentist. They will have access to sufficient housing."