Labour is going to ask the Auditor-General to investigate the Ministry of Health's refit funding botch-up.
Opposition MPs have lashed the Government over the ministry's financial mismanagement and they're saying there must be an inquiry.
Labour's health spokeswoman, Annette King, says she's taking it to Auditor-General Lyn Provost.
"Let's have the Auditor-General have a look at this whole issue and report back to Parliament," she said.
"It will be transparent, it will be open, and the public will know what happened."
The ministry believed it could pay for a $24 million head office refit from its cash reserves, but because of a forecasting blunder it came up $18m short.
It has found a solution through a lease agreement and says it won't have to ask the Government for extra money, but the Treasury has criticised it for its poor financial management.
Labour called a snap debate in Parliament on Tuesday and party leader Andrew Little lashed out at Finance Minister Bill English and Health Minister Jonathan Coleman.
"This has been an absolute failure by those charged with responsibility and we know who will pay the price - not just the taxpayers but the patients who will go without hospital surgery and pharmaceuticals," he said.
Dr Coleman said the ministry had made a mistake, and had admitted it.
"That was totally unacceptable and I have made it clear it can't happen again."
Dr Coleman said the money for the refit wasn't going to come out of the ministry's operational funding.
"It doesn't take one dollar away from patient services."