The speech gave only one definite example of "nice-to-have" spending.
"An obvious place to start is suspending new payments to the New Zealand Super Fund for the next four years," Goldsmith said. "That alone would reduce core Crown debt by $9 billion over four years."
Later Goldsmith confirmed the move was National Party policy. The move would not be without precedent.
When National came to power in 2008, Finance Minister Bill English announced that payments to the fund would be suspended while the country was in deficit.
The move would come under criticism as NZ Super - and financial markets in general - experienced strong returns over the following decade, well above the cost of borrowing.
Repayments only restarted when Grant Robertson became Finance Minister.
Borrowing costs have only continued to decline in this term of Parliament, but Goldsmith said continuing to make payments to NZ Super while the Crown accounts were in large deficits was like a household borrowing money to put on the sharemarket.
"There's arguments both ways, but ultimately the total amount of debt that we're taking on is an issue, and fundamentally, there's not too many individuals going out to borrow money to put it on the sharemarket, which is effectively what we're doing," Goldsmith said, adding that he was not ruling out restarting contributions later.
"At a time when we're borrowing tens of billions of dollars, we don't think it makes sense to borrow even more to put it aside for the Super Fund."
Goldsmith said Labour's forecasts would see net debt rise to almost 54 per cent of gross domestic product by 2024.
"That's an eye-wateringly high level," Goldsmith said.
"There is every reason, given the spending patterns of the past three years, to believe that a returned Labour-led government would take it higher than that."
The speech also confirmed that National would delay April's planned hike in the minimum wage to $20 an hour, as well as putting a freeze on introducing new regulations for at least 18 months, except in emergencies.
He also delivered a sharp criticism of Treasury.
"During a crisis, such as this, we can't lose sight of the normal disciplines of spending – prioritising spending, making tough choices, focusing on results," Goldsmith said.
"My starting point would be a rebooting of Treasury's capacity and authority within the public service on spending. In our view, Treasury has lost the capability to fulfil its role as a watchdog on Government spending."
