The Government does not know how many children will be lifted out of poverty as a result of last week's Budget and Opposition parties say that is not good enough.
Social Development Minister Anne Tolley said while there was no estimate of the impact on poverty, the initiatives in the Budget would help many poor families.
From April next year, beneficiary families will get an extra $25 although the benefit increase for many is likely to be offset by cuts to other allowances.
But Prime Minister John Key said the Government was not able to say exactly what effect that increase would have on poverty.
"The question is how many people does the change in benefits move out, benefit increases, move out [of poverty]. I asked [Ministry of Social Development official] Bryan Perry that question and the answer is that it will move some people out. He was quite convinced that actually it would make a difference but exactly how many people it'll move out in total I don't know," Mr Key said.
So does Mrs Tolley know how many children will be lifted out of poverty?
"No, because we went wider than that in the end and we've got, you know, the whole package - almost 500,000 children will benefit in some way," she said.
Labour children's spokesperson Jacinda Ardern said it was incredible the Government was not measuring the impact of the changes.
"Surely if you were focusing your initiatives on trying to lift children out of poverty and families out of poverty that you would have thought they would have at least asked Treasury or the Ministry of Social Development to do some calculations to estimate how many genuinely would," Ms Ardern said.
Green Party co-leader Metiria Turei said she was not surprised.
"I expect that John Key and the Government will continually say that they don't know how many children will be brought out of poverty by these measures because they haven't set in place any system to be able to identify those kids, to be able to measure their incomes in the short and medium term and then to be able to measure whether any intervention is working," Mrs Turei said.
In recent weeks, the Government had also focused on the 60,000 to 100,000 children it said were in the worst hardship.
Mrs Tolley said that was based on a material deprivation index which looked at 17 different factors - such as having two pairs of shoes and how often a child ate meat.
If they were missing out on at least nine of these, they were deemed to be in extreme hardship.
Opposition parties accused the Government of trying to shift the debate on poverty by changing the definition to reduce the number of children in hardship.
They said there needed to be a consensus about how to measure poverty.
New Zealand First leader Winston Peters said he agreed.
"We need to come to some sort of agreement but, you know, there's enough international science and study behind this for us to know what it is.
"But basically if you've ever been poor, real poor that is, and you know what it smells, tastes and feels like you don't need some international measurement to tell you what poverty is," Mr Peters said.
The Government said, whatever the arguments about what constituted poverty, the package in the Budget would help poor families.