Communications Minister Stephen Conroy has warned mining magnate Gina Rinehart not to trash the Fairfax Media brand for other shareholders.
Mrs Rinehart reportedly is seeking three seats on the media company board after she recently increased her stake to 18.67 per cent.
Fairfax newspapers say Ms Rinehart wants to be appointed deputy chair of the company and have two other board positions for her representatives, which would include Hungry Jack's founder Jack Cowin.
Senator Conroy says Australia's richest person is entitled to representation on the Fairfax board.
"What she's not entitled to do is trash the brand for all the other shareholders," he told ABC radio on Tuesday.
Senator Conroy said an independent charter of editorial independence had been supported over many years by the company's board.
"If she was to directly interfere and breach that charter it would actually lead to a crisis of confidence among the readership," he said.
"If the readership deserted then the share price for every shareholder would decline."
Senator Conroy was responding to reports Mrs Rinehart does not want to be limited by the charter.
He said the billionaire could put to bed any board opposition by signing up to the charter.
Senator Conroy said it appeared Ms Rinehart wanted to override the chief executive appointed by the existing board.
"This is clearly not in keeping with charter of editorial independence," he said.
Ms Rinehart was entitled to turn the Fairfax newspapers into "the mining gazette" but the company's other shareholders needed to know about that.
Senator Conroy said Ms Rinehart was not breaking any existing laws.
"I'm not sure government can do a lot when it comes to maintaining the independence of journalists and editors from boards of companies."