Prime Minister Scott Morrison says a cabinet minister subject to an allegation of rape in the 1980s is entitled to be presumed innocent.
Greens senator Sarah Hanson-Young, Labor's Penny Wong and Prime Minister Scott Morrison were sent a letter detailing the complaint last week.
The incident is alleged to have occurred in 1988 when the woman was 16.
The woman went to NSW police last year, but the investigation was suspended when she took her own life after telling authorities she didn't want to proceed.
Mr Morrison told reporters in Sydney he had been briefed on the contents of the letter and spoke with the minister on Wednesday last week.
The minister had "vigorously rejected" the allegations, he said.
Mr Morrison said he had also discussed it with the federal police commissioner and senior officials in his department, but did not plan to take any action beyond leaving the allegations in the hands of police.
"There are no matters that require my immediate attention," he said.
"These are very distressing issues that have been raised, as there are other issues that have been raised in relation to other members in other cases, but the proper place for that to be dealt is by the authorities, which are the police.
"That's how our country operates. That systems protects all Australians."
Minister for Women Marise Payne said the rule of law should apply.
ACTU secretary Sally McManus said the prime minister had the power to act, based on the probability of a crime occurring.
"The prime minister can decide who sits around that cabinet table and drop them for any reason they want," Ms McManus told the ABC.
"If they think that it's likely that it did happen then they should not be there."
Senator calls for minister to stand aside
Senator Hanson-Young believes the minister must stand aside pending an independent investigation by an eminent former judge.
"It is just not right to suggest that this type of allegation could linger, hang over the heads of the entire cabinet," she told ABC radio.
"Sitting around that table erodes the trust the integrity and belief that this government takes sexual assault seriously."
Mr Morrison said the "mere making of an allegation" should not be grounds for a person to be stood down.
Marque Lawyers managing partner Michael Bradley, who represented the woman when she took the complaint to police, questioned whether the minister could do his job with his integrity under question.
"I think he will have to stand aside, at the moment at least, because he's been accused of such a grave crime," Mr Bradley told Nine newspapers.
"It's untenable for him not to, I would think. It's not really a legal question, it's a question of propriety."
Police told of allegation of rape against a serving Labor MP
Liberal senator Sarah Henderson has forwarded police an email from a woman who claims she was raped by a serving Labor MP.
The AFP confirmed they received a complaint relating to a historical sexual assault but would not comment further.
Sexual assault allegations have sparked national debate about political culture after former Liberal staffer Brittany Higgins said she was raped by a colleague in Parliament House.
Four inquiries are under way, including a multi-party investigation aimed at ensuring parliament is a safe working environment.
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