Regional Development Minister Shane Jones has climbed into the leadership of dairy giant Fonterra, calling for chairman John Wilson to follow chief executive Theo Spierings out the door.
Jones said he told the company it should stop being political and instead focus on its business.
"They should focus less on interfering in politics and more on justifying the money they've lost overseas. I believe that they have become disconnected from the farming community."
Jones said he had suggested to Agriculture Minister Damien O'Connor whether it was time to restructure the dairy co-op, and singled out Wilson for special mention.
"The leadership of Fonterra, I believe, starting with the chairman, is full of its own importance and has become disconnected."
He said there was an absolute absence of accountability for the "enormous amounts of dough" that the current chairman had presided over.
"The CEO has gone, well that's only one party of the double-Dutch we've had to put up with in Fonterra over the last nine years. I thoroughly believe this ... that as the CEO leaves Fonterra, the chairman should in quick order catch the next cab out of town.
"I've been bloody disappointed that Fonterra, in my view, the leadership has not accepted that there's a new Government and there is a new narrative and I've had a gutsful of them believing they are bigger then what they really are."
Wilson and Fonterra did not immediately respond to a request for comment.
Jones said later that farmers backed him and had left messages of support on his phone.
He said he had been invited to speak at a breakfast meeting at Fieldays today.
His ire was raised when the meeting was subject to Chatham House rules and the media were banned.
"My target is well and truly around the hubris of the chairman and the board and I know that National MPs agree with me."
It is the second time in as many months he has taken aim at the board of a high-profile company.
In March he suggested Air New Zealand chairman Tony Carter should step down.
"Obviously you'd start with the chairman ... I'm telling that board, in terms of the growth and connectivity in provincial New Zealand, it will not increase unless that board changes," he said.
Jones, who has been highly critical of Air New Zealand's decision to cut flights to Kapiti, also warned Air New Zealand chief executive Christopher Luxon to butt out of politics.
"Do not poke your nose into the political boxing ring unless you're going to resign today and join the ranks of the National Party. This is a legitimate issue on behalf of those provincial areas who have been shortchanged. I've said all along, my focus is on the board."
National's regional economic development spokesman Paul Goldsmith said it was time Prime Minister Jacinda Ardern pulled Jones into line.
"Shane Jones' attacks on Fonterra's leadership are the latest burp from a man who is fast losing any respect he once had. He says Fonterra's leadership is 'full of their own importance'. That sounds like a more apt description of himself," Goldsmith said in a statement.
"He even added he's 'worried about the absolute absence of accountability for the enormous amounts of dough that the current Fonterra chairman has presided over'.
"This is startling hypocrisy from the same man who defended his own region getting the lion's share of funding from his billion-dollar Provincial Growth Fund by stating 'to the winner goes the booty'.
"Well it's not his booty and it's clear Shane Jones has no idea what accountability means.
Fonterra is currently hunting for a new chief executive to replace Spierings but Wilson has been quiet about his own future plans.
He has been on the Fonterra board since 2002 and became chairman in 2013.
In March, former Fonterra director Harry Bayliss sent an email to board members calling for Wilson to step down.
Bayliss, who served on the board from 2001 to 2006, told the Herald he did not believe the board had taken the opportunity to deliver on value-add opportunities.
"I honestly believe that the chair needs to be held accountable in that regard," he said.
"He needs to be prepared to put his hand up say 'I will be held accountable for this' and move on."
Bayliss pointed to the WPC80 product recall and subsequent $183m settlement with French food group Danone and the ongoing underperformance of China's Beingmate, in which Fonterra has an 18.8 per cent stake.