Health, housing and education are set for a major funding boost from today's Budget.
The Prime Minister is playing down expectations, saying it will be predictable and based on the core issues they campaigned on at the election.
She's dubbed it the "rebuild" Budget.
"This very much is about getting back to those services that really affect New Zealanders, making sure that we're investing in them."
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National says its nine years in power set the new Government up for a strong Budget - but leader Simon Bridges says they'd approach it differently.
"We wouldn't be - given the strength of the books, given the strength of the economy - putting on more taxes, more borrowing."
He's predicting a Budget of "broken promises".
"Whether it's 1800 police they are not delivering, whether it's KiwiBuild that is becoming more and more of a shambles, whether it's universal cheaper visits, they are not delivering," he told Newstalk ZB.
"I think in the absence of a plan that's what you get - broken promises."
The Government has already delayed cheaper doctor's visits, as well as the KiwiBuild policy - and changed how much those houses will cost. Ms Ardern says they couldn't achieve everything at once.
"We've also had to balance priorities too. There's been a number of competing ones that we've had to phase because we can't do everything at once."
Labour promised 1800 more police over three years, but is now looking at dragging that out to five years.
National finance spokeswoman Amy Adams said there is "plenty of money" and "there's no reason at all they should be breaking trust with New Zealand".
"This is a Government awash with cash," she told The AM Show on Thursday.
"They have huge and growing surpluses left to them thanks to the good management of our Government. They've borrowed another $10 billion and they've already put up taxes by a further $2 billion from a Government that said 'no new taxes'. So there's plenty of money."
Labour promised no new taxes in its first term. It's likely Ms Adams' claims of a $2 billion tax hike is referring to National's planned tax cuts, which Labour cancelled in favour of more targeted spending on its families package.
Ms Adams denied claims National neglected struggling Kiwis by ignoring the housing crisis and inequality.
"It's absolutely not true… we came through long-running deficits left to us by Labour, a country in recession before we even got to the [global financial crisis], the earthquakes. We recovered from all of that."
The previous Labour Government actually posted eight successive surpluses. GDP growth turned negative at the start of 2008, while the financial crisis is generally considered to have gone global later that year with the collapse of US investment bank Lehman Brothers.
"We absolutely did the best job in the times we had," said Ms Adams. "Of course there's still more to do."
Tune into a Newshub Nation special for all the details from 2pm.