The woman alleges the former Liberal Party staffer reached under the table to stroke her thigh at a Canberra bar in 2017.

She has filed a report at a police station in Canberra and will make a formal statement later this week.

The woman came forward to the ABC after Brittany Higgins alleged she was raped by the man in 2019.

Two other women – a Liberal staffer, and a former party volunteer – have also alleged they were sexually assaulted by him.

The third woman to come forward says she was assaulted while working as a coalition volunteer during the 2016 election campaign.

She was barely out of school at the time of the attack, which allegedly occurred after a night out drinking with the then-political staffer.

Higgins was employed by Defence Minister Linda Reynolds at the time of her alleged rape.

She initially chose not to pursue a police complaint, fearing her job would be on the line.

Reynolds faced multiple questions in parliament about her meeting with an Australian Federal Police assistant commissioner regarding the incident.

“What we discussed in those meetings is not my story to tell,” the minister said.

“I have always, and I continue, to respect her privacy and her story.”

Prime Minister Scott Morrison is maintaining his staff didn’t tell him about the allegation until days after media raised questions with his office.

“I’ve instructed my staff I would expect to be advised of such matters,” he told parliament.

“I look forward to the police progressing this matter and any other matters that may be related to this in terms of any other alleged offences, in relation to this individual.”

Greens leader Adam Bandt asked if the man accused of the assaults held a lobbyist pass or attended parliament after being sacked as a ministerial adviser.

The prime minister said records would be checked.

Labor’s upper house leader Penny Wong lashed the government’s response to Brittany Higgins.

“She wasn’t being treated as a human being. She wasn’t being treated as a rape survivor and she wasn’t being treated as a victim of a grave crime,” she told parliament.

“She was being treated as a political problem.”

Wong said Morrison’s words rung hollow while there was no culture of accountability.

“We know that at best, Mr Morrison runs a government where the culture is don’t ask, don’t tell when it comes to serious criminal allegation,” she said.

“At worst, Mr Morrison himself is part of the cover-up.”

Labor, the Greens and One Nation have accused the government of setting up whitewash inquiries in response to the allegations.

The alleged rape has sparked several inquiries into workplace culture in federal politics.

The prime minister has also endorsed an external complaints handling process for parliamentarians and their staff.

He has tasked Department of Prime Minister and Cabinet secretary Philip Gaetjens – who is also his former chief of staff – with a separate review of what his staff knew and when.

The Greens are calling on the government to set up an independent review into how Higgins’ allegations were handled.

The second woman to come forward over the weekend said her assault may have been avoided if Higgins’ complaint was dealt with properly.

Independent MP Zali Steggall wants independent investigations to accept anonymous reports after being contacted by former staffers with traumatic stories about their time in parliament.