New Zealand First leader Winston Peters has swung in behind his MP Shane Jones, joining him in savaging Fonterra and its chairperson.
Mr Jones - who is Regional Development Minister - yesterday attacked the dairy giant, saying it needed to be restructured and its chair should "catch the next cab out of town".
Mr Peters defended the comments and said "heads should roll" at Fonterra.
"It goes to the top and the buck stops there," he said.
"I can't believe somebody responsible would be in the job still."
In March, the dairy cooperative announced its first ever loss, of $348 million for the six months to September.
"A massive hundreds of hundreds of millions of dollars loss needs an explanation ... there needs to be some accountability," Mr Peters said.
At Parliament, Mr Jones told reporters he stood by his criticisms which he said he made in his personal capacity.
"From time to time in MMP coalition government, a robust NZ First politician such as myself should be entitled to serve notice on these corporate aristocrats at Fonterra."
Speaking at Fieldays in Hamilton, Prime Minister Jacinda Ardern endeavoured to distance the government from Mr Jones' comments.
"Ministers share personal opinions all of the time, but what I'm making clear here is was he said is not government policy ... end of story."
Ms Ardern said she would not be disciplining Mr Jones as he made clear his comments were his own opinion.
National economic development spokesperson Paul Goldsmith said NZ First was in "open defiance" of the Prime Minister.
"The last time Shane Jones got on his high horse and started attacking business leaders she said that that was a step too far.
"Now he's done it again - and instead of saying 'that's your second strike', she's saying, 'oh it's a personal opinion'."
Mr Goldsmith said the excuse was "weasel-words".
"He is a minister of economic development, talking about New Zealand businesses ... he's not entitled actually to a personal opinion. He's the minister."
The Prime Minister's weak response proved she could not control the NZ First Ministers, Mr Goldsmith said.
"The government has no coherence and internal discipline."