Labour leader Andrew Little has been called a "doofus" by the Health Minister in an often ill-tempered debate on financial management at the Ministry of Health.
An urgent Parliamentary debate was granted yesterday after it emerged the Ministry of Health had bungled a financial forecast and had to ask the Government for $18 million.
Labour has accused Health Minister Jonathan Coleman of covering up the embarrassment.
Mr Little said the director-general of health, Chai Chuah, had been made to take the heat for the problem.
"He may have some responsibility, but it is the ministers ultimately who are to blame," Mr Little said.
"It was their job to ask the simple questions. Because when you say you have a spare $24 million dollars of reserves, it does raise an obvious question ... really? How much underspending have you had to do?"
Had that question been asked, the bungle would have been discovered and the project would never have been signed off, Mr Little said.
"We have to call this to account ... If you are wondering why you cannot get your melanoma drug treatment, if you are wondering why you can't get your surgical treatment ... look no further than the Minister of Health and the Minister of Finance."
In response, Dr Coleman said Mr Little was boring and had failed to win the New Plymouth electorate in two attempts.
"I have a number of messages for Annette King, actually. But I tell you, Mr Speaker, if she is going to let that doofus take over her seat at the general election, she's going to end up - " Dr Coleman said, cut off by a point of order by Ms King.
At two other points during Dr Coleman's speech, in which he criticised Labour MPs, Deputy Speaker Chester Borrows interjected, advising him to return to the issue.
Dr Coleman said he was responding to the "character assassination" and "scurrilous attacks" from Labour.
The controversy relates to a refit of the ministry's Wellington head office. That was approved by the Government in 2014, after the ministry said it could use forecast reserves to meet the $24 million cost.
However, the ministry later learned its financial team had miscalculated, and before the last Budget it put its hand out to the Government for $18 million to finish the job.
In a statement, Mr Chuah said unacceptable mistakes had been made. He had ordered an independent review to establish what had occurred and ensure it would not happen again.
Funding needed for the refit was being secured by spreading the cost over the life of the building's lease, he said, which would be "fiscally neutral".
Ms King has countered the claim the lease would be "fiscally neutral", saying it seemed extremely suspect.
She expected it would be paid for by increased rent to the landlord.