Prime Minister Tony Abbott says he didn't have a discussion with Fiona Nash about resigning from the ministry over conflict-of-interest issues involving her former chief-of-staff.
The Assistant Health Minister faced a heated grilling during a Senate estimates hearing in Canberra on Wednesday when she again was accused of misleading parliament over the appointment of Alistair Furnival.
Mr Furnival resigned after failing to divest a shareholding in his wife's public relations company Australian Public Affairs - a requirement of his appointment - which had links to the junk food industry.
A number of controversial decisions were made in the minister's office, including the removal of a food rating website opposed by the industry.
Senator Nash refused to say whether she had offered her resignation to the prime minister over the issue.
"I am not commenting on any discussions I had with the prime minister or the prime minister's office," she said.
Mr Abbott later defended his minister and described the Furnival matter as a "fairly minor", despite the "huffing and puffing" of non-government senators, including Labor's Penny Wong.
"I've had no such conversation with her," he told reporters, adding Senator Nash's decisions were "eminently justifiable".
During her appearance before the committee, Senator Nash said she was aware of Mr Furnival's links to the food industry before he was hired.
But she rejected Labor claims she misled parliament by initially denying any connection.
"At no point did I intend to mislead the Senate," the junior minister said.
"My mind, I do have to say, was turning to the issue - was there separation between my chief-of-staff and the business."
Senator Nash said she went back to her office and reflected on her initial response.
"I recognised that I did need to provide additional information ... to ensure there was clarity around that," she said.
Veteran Labor senator John Faulkner was unimpressed, noting it took the minister six hours to correct the record.
"You now claim to be aware ... it doesn't stack up, they can't both be right," he said.
Senator Nash said she had undertakings from APA that it would make no representations to her, her department or Health Minister Peter Dutton, or any other minister relating to the health portfolio.
"My chief-of-staff gave a series of undertakings ensuring a strict separation between the business of APA and himself," she said.
Senator Wong accused Senator Nash of again misleading parliament, saying Mr Furnival had only resigned as a director of the company on February 13, two days after the minister's initial statement to the Senate.
He also maintained a shareholding in the company which owned APA.
Senator Nash rebuffed the claims, saying Mr Furnival had told his accountants to divest him of all directorships at the outset of his employment.
That divestment was "underway".
The minister refused to table a letter from Mr Furnival in which he outlined his undertakings.
"I am not going to provide you with internal communications," she said.
