The Green Party is planning to extend the early-childhood education subsidy to 2-year-olds to ensure all children had enough to thrive.
It was the first of what the party said would be a series of measures targeting child poverty and inequality.
The party also said it would provide an extra $32 million a year to fund qualified early childhood education (ECE) teachers "as part of an ambitious plan to boost the quality of early-childhood education and make sure every child gets the right care and support".
The party said the policy, which extended the 20 hours a week free ECE already provided for 3 and 4-year-olds, would carry an initial cost of $297 million, rising to $367m in four years time.
It would cover 40,000 children, saving families with 2-year-olds in ECE an estimated $95 a week.
"Every child should have enough to thrive," co-leader Metiria Turei said.
"Any less is a failure of society."
Turei pointed to a 2010 OECD study that showed working New Zealand families spent 28 per cent of their net income on childcare.
"The Green Party will help families out financially by reducing early-childhood education costs, at the same time as improving access to quality education," she said.
"It is a major investment in our kids."
About two-thirds of all 2-year-olds were enrolled in ECE but did not get the subsidy, she said.
The Greens also wanted to ensure the education ECE offered was high-quality.
They would therefore fund more qualified teachers, commit to a long-term strategy for lifting teacher qualifications, and hold a ministerial review into ECE funding that would also look at staff ratios and focus on expanding the not-for-profit sector.
The party has already announced a policy to build 20 new ECE centres at low-decile schools.