Grant Robertson outlined where the funding for the extra $24 billion needed would come from for Budget 2018.
"The government's Budget allowances over the next four years and 100-Day Plan spending is about $24 billion higher than planned by the previous government for the years 2018/19 to 2021/22," the Finance Ministry said in statement.
Of the $24b, $7.9b comes from the reversal of National's taxcuts.
"This will fund the Families Package and other 100-Day-Plan commitments."
Nine billion dollars would be pulled from "adopting a responsible debt reduction track", $5.3b would come from "higher tax revenue driven by higher-than-expected economic growth". and $1.5b would come from change to New Zealand's tax system and reprioritisation of funding.
Reprioritisation is pulling money from other sectors.
As part of the reprioritisation, the Provincial Growth Fund, costing $1 billion per year, will pull $148m of existing funding as part of its operating costs, including $75m from the Tourism Infrastructure Fund and $13m from the Budget 2017 Between-Budget contingency.
The Growth fund took $80m of existing funding to go towards capital, which could take a portion "of KiwiRail's capital injection for the 2018/19 financial year."
Prime Minister Jacinda Ardern has fired back at the National Party following claims likening the Budget to an algae and mould cleaner.
The Budget was referred to as "spray and walk away" by the Opposition, Ms Ardern said in parliament today.
"At first, I thought it was metaphorical, until I reminded myself that this is a cleaning product for algae and mould removal, rather than a jibe at maybe a legitimate tip from the leader of the opposition to clean up our rivers and our hospitals."
"It is, however, a shame that the rest of the mess will take more than 30 seconds to repair," Ms Ardern added.
The Prime Minister's response was met with a round of applause in the debating chamber.