The Children's Commissioner is urging the Prime Minister to "put children first" and reconsider her support for punitive drug sanctions for beneficiaries, including for those with kids.
Only a tiny numbers of beneficiaries fail a drugs test each year - in the year to June almost 40,000 people were referred for jobs that required a drugs test and there were only 114 failed results.
Nearly two-thirds of those were sanctioned, and beneficiaries with children can have half of their benefit taken from them.
Children's Commissioner, Judge Andrew Becroft, says the policy is unjust.
"Children shouldn't be penalised for the actions of adults over which children have no control - I think it is unprincipled and as Children's Commissioner I would be derelict in my duty if I didn't say please reconsider," Judge Becroft told 1 NEWS today.
"Children need to be put first, there are other solutions and frankly parents that are struggling with addiction need help and counselling and intervention - but I don't know that we can punish our way out of this."
Judge Becroft had a message for Ms Ardern: "Please reconsider, please ensure children are not disproportionately affected by the actions of those adults that they have no control over, and putting children first will mean we don't make poverty worse for them."
But the Prime Minister said today that only "a very very small number" of benefits are being cut.
"The expectation of course is that benefits will never be fully removed for those with children in their care - that wouldn't be right."
1 NEWS asked a range of senior Labour ministers what they made of the policy.
"It would make life challenging, but that is the situation at the moment," Kris Faafoi the associate Housing Minister said.
"I think you'll find this Government is about health and wellness of all our communities and we do what's best for our children - but you better ask (Social Development Minister) Carmel Sepuloni about it," the Police Minister Stuart Nash said.
"You've already asked those questions of the Prime Minister and the Minister, they're the appropriate people," Finance Minister Grant Robertson responded.