Ardern used what is known as the after-housing costs measure to argue her case for successfully combating child poverty.
That showed that after housing costs, 235,400 kids lived in homes with less than 50 per cent of the overall median household income, in the year to June 2019.
That's a drop of 18,400 children, or a 2 per cent fall compared to the previous year.
While there are nine measures of child poverty, the Government has chosen to highlight three with specific three and 10-year targets.
Those are the before and after housing costs of the bottom 50 per cent, as well as the overall material hardship level.
Bridges used the numbers to suggest child poverty was getting much worse "under Jacinda Ardern".
He used the before-housing cost measure for the bottom 60 per cent of households and compared the year to June 2017 figures with those from 2019.
On this measure, the 20,000 figure is correct – 243,300 kids were in this category in 2017, compared with 263,400 in 2019.
But Stats NZ publishes numbers a year in arrears meaning much of the increase cited by Bridges actually occurred in 2016-2017; under the former National government.
That year, there was a 40,000 lift in the number of kids in the before-housing cost measure; from 243,300 to 281,200.
But while Ardern and Bridges trumpeted their arguments, the most important measure – according to Children's Commissioner Andrew Becroft – was actually increasing.
Material hardship, which measures the things most people would consider to be essentials – such as access to fresh fruit and vegetables, going to the doctor and the ability to pay bills on time – increase by just over 4000 in the year to June last year.
Ardern was quick to point out that the measures in the data don't fully take into account the full impact of the $5.5 billion Families Package.
Becroft said he was disappointed that today's figures did not fully measure the impact of the Families Package.
He said it was the best and deepest data to date seen on child poverty– "it's probably the most accurate picture that we have ever had, but it is a case of wait and see".
He said he could not give the Government a pass or fail grade based on the results – "you could maybe be cautiously optimistic, but we still have to see the proof in the pudding, as it were".