Australia's prime minister apologised for widespread sexual harassment, abuse and bullying of political staff Tuesday, a year after a high-profile rape allegation rocked the country's parliament.

Addressing lawmakers, Scott Morrison apologised directly to former staffer Brittany Higgins who said she was raped by a male colleague in a minister's office in 2019.

"I'm sorry to Ms Higgins for the terrible things that took place here," Morrison said describing a decades-long culture of abuse in the corridors of power.

"But I am sorry for far more than that -- for all of those who came before Ms Higgins and endured the same."

"Over many decades, an ecosystem, a culture, was perpetuated where bullying, abuse, harassment, and in some cases even violence, became normalised," he said.

Higgins went public in January last year, sparking nationwide protests.

Australians were shocked by the alleged abuse she experienced, but also the way she was treated when she told her bosses.

She said she felt pressured not to go to the police ahead of the 2019 election and described a "culture of silence" in Australian political parties.

In the wake of Higgins' allegations, and those of other staffers who came forward after her, the government launched multiple inquiries.

One of those, the 450-page Jenkins Review, found that one-in-three people currently working in Commonwealth workplaces have experienced sexual harassment while working there.

In his speech, Morrison said: "This has to change. It is changing. And I believe it will change."

Opposition leader Anthony Albanese also offered an apology to Higgins from his Labor party.

"You have torn through a silence that has acted as the life support system for the most odious of status quos," he said.

Listening from the public gallery, Higgins became visibly emotional during the speeches.

She sat between three fellow former staffers who have gone public with their own allegations, and two women's rights advocates.

The women were asked to attend the formal acknowledgement after they tweeted the night before about not being invited.

Higgins will speak Wednesday at the National Press Club alongside sexual abuse survivor Grace Tame, who was the 2021 Australian of the Year.

Tame dismissed the prime minister's apology. "How about some proactive, preventative measures and not just these performative, last-minute bandaid electioneering stunts?" she tweeted Tuesday.