The National Government resisted constant calls from its Children's Commissioner and others for the broad statistical targets the new Government has now adopted. Bill English believed poverty would be better tackled by programmes targeted more precisely at individuals and households that need specific help.
As Finance Minister he convinced National to publish a set of concrete targets in fields such as disease reduction and educational pass rates which, to his expressed regret, the Ardern Government has just abandoned.
Now she is urging National to support legislation that would require the broad, income-based targets to be part of all future Budgets. Political calculations certainly favour Labour's sort of targets.
By simply raising benefit and income support payments, or promising to raise them, a political party can claim to raise a big round number of children above its chosen "poverty line".
English succumbed to this temptation at last year's election when he boasted that his 2017 Budget would lift 50,000 children above the line this year. The fact the Treasury has subsequently admitted it miscalculated that figure, and the larger figure it put on Labour's benefit promise, underlines just how theoretical this measurement of poverty really is.
But, undeterred, Labour is persisting with it, the Prime Minister has made it her personal mission in politics and National may find it politically too difficult to oppose it.
Poorly targeted increases for all low income and benefit-dependent households might not significantly improve the situation of children in real hardship but it will reduce inequality, which may be this Government's real purpose.
So long as it can maintain economic growth it will be able to gradually lift all family incomes to within 50 per cent of 60 per cent of the median, calculated before or after housing costs.
If it cannot maintain economic growth and tax revenue does not kept pace with its poverty reduction targets, something will have to give. But in the meantime, alleviating child poverty by any measure will be a popular effort.