Finance Minister Grant Robertson will not commit to getting a political-promise costings unit off the ground before the next election.
Labour and the Greens had both wanted to establish an independent costings unit which could vet political promises and ensure they were costed appropriately.
In April, National's new finance spokeswoman Nicola Willis reversed her party's prior position and threw its support behind an institution too, writing to Finance Minister Grant Robertson saying she would be keen to support such an office.
Robertson said it was too late to fund the office as part of Budget 2022, but said he remained open to such a unit being funded in the future.
"I note the change in position expressed by the National Party. I continue to be interested in exploring the option of establishing an institution, as resources and other priorities allow, but regrettably it is too late to be considered as part of Budget 2022," Robertson said at the time.
Asked recently whether work had begun on establishing a unit, Robertson noted the Government had to balance such a unit against other priorities the Government currently had - a suggestion it may not be funded by the next election.
Ministers are currently at the very early stage of putting together proposals for the next Budget.
Labour still supports the idea - just perhaps not now.
Supporters of the costings unit are calling on Robertson to fund the project and have it up and running for the next election, in particular the Greens, with whom the idea originated.
Green Party Finance spokeswoman Julie Anne Genter said, "[w]e need an independent and publicly-funded source that helps parties and the public understand the impacts of the policies they are campaigning on. I imagine most people would be very pleased to know that come election time they will have access to unbiased information about a party's policy figures.
"It would take us a step closer to what elections are supposed to be: a contest of ideas, not spin," she said.
"The Green Party has long supported an independent costings unit for election policies. We first proposed it back in 2016 and took the idea into Government, where we started consulting how it could work, before National killed it off.
"Now is the time for the Government to make good on what has long been a very good idea and fund an independent fiscal institution in next year's Budget," she said.
Willis said it was "disappointing" the office might not be funded by the next election.
"It's hard to see it as anything but cynical. Here was something in principle Labour thought was important for New Zealand's Parliament and our democracy and our election campaigns and yet the minute National said 'let's work together on that' they seem to have shied away from it," Willis said.
She said Labour should at least have a discussion with National about what might be achievable before the next election.
Act leader David Seymour, however, said it was not up to unelected officials to decide what was true and what was not.
"Democracy is under assault from the idea we can't trust voters and politicians so unelected officials must be gatekeepers to office and this is another example of that," Seymour said
"It's hard enough fighting the bureaucrats after you're elected let alone making them gatekeepers to election," he said.
Seymour said he did not want to fight with an "unelected official's view of the world" before he was able to put his policies in front of voters.
"Some people believe that cutting taxes will lead to more growth, others dispute that - why should an unelected official rather than voters and candidates get to resolve that dispute?" Seymour said.
Labour and the Greens still support establishing some kind of costings unit and National this year changed its position, swinging its support behind such an office as well, giving Robertson enough consensus to have one established.
The costing unit idea was a 2017 idea from the Labour and Green confidence and supply agreement. The idea was to take the heat out of the "fiscal hole" controversies of the last decade by creating an independent referee in fiscal debates.
Robertson tried to establish the unit as an Officer of Parliament, which would have made the institution highly independent from the executive, and responsible to Parliament instead of Cabinet, similar to the Auditor-General to the Ombudsman.
But establishing it as an Officer of Parliament required political consensus, meaning in practice that at least National had to support it.
Documents released under the Official Information Act said the office could cost as little as $1 million a year and as much as $10 million a year to run.