Opposition MPs are divided over whether Assistant Health Minister Fiona Nash should resign over the role a senior staffer played in the removal of a food ratings website.
Labor backbencher Rob Mitchell said time was up for the minister.
"Fiona Nash should have some form of decency and resign," he told reporters in Canberra on Thursday.
But Labor's health spokeswoman Catherine King was more restrained.
"There are more questions to be asked," she said, adding the minister's resignation was a matter for the prime minister.
But she was more adamant about the latest revelations involving her former chief of staff, Alastair Furnival.
Mr Furnival previously worked for Cadbury and lobbied on behalf of the company to secure $400,000 for a visitor centre, Fairfax Media reports.
The coalition, in opposition, committed $16 million to the project.
"Something absolutely stinks about this," Ms King said.
Mr Furnival resigned from Senator Nash's office after he failed to divest a shareholding in his wife's lobbying company in breach of the ministerial staff code of conduct.
The firm acted for clients in the food industry, some of whom opposed the food ratings website which Mr Furnival ordered removed.
