National says the opening of the government books yesterday backs up its argument that Labour has a massive hole in its accounts.
Labour says the accounts show it can make good on its election promises, and on the deals struck with New Zealand First and the Greens.
The government said it would pay debt down more slowly and cancel National's tax cuts.
Finance Minister Grant Robertson said it was also committed to running sustainable surpluses across the economic cycle.
"But it does have the same caveat that every government has, that if there is a big major natural disaster then obviously we take that into account in terms of whether we can run a surplus or not."
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National's finance spokesperson Steven Joyce said it was now clear just how incredibly tight it was going to be for the government over the next few years.
"With all the things they've promised that aren't in there, they've given themselves very little room and that's why they are arguing for about $350,000 over Kidscan and all this very small stuff, because it is so incredibly tight for them.
"So I think we'll see that continue to grow, they've got debt going to $70bn over the next three to four years."
Mr Joyce said Labour was continuing a growing in the "spagetthi of entitlements" which were getting "more and more complicated".
"Grant Robertson, on his absolute tippy-toes, has shown that he can almost make the budget work."
Mr Joyce said the Half-Yearly Economic Update omitted a number of things including funding for police and the America's Cup.
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Parliament went into urgency last night to push through the government's $5.5 billion families package.
The package includes an extension to Working for Families and a boost to the accommodation supplement, a payment for young babies, and a winter payment for superannuants and most beneficiaries.
Prime Minister Jacinda Ardern said the package meant more than 380,000 families would get on average $70 a week more.
"This is a package that means, by the time its fully rolled out, we will have reduced child poverty in New Zealand by 48 percent."
The house will resume at 9am to continue debating the bill.