Scott Morrison Photo:Xinhua

Australia's Prime Minister Scott Morrison on Tuesday apologized to a political staffer who said she was raped in a ministerial office, after a review found half of parliamentary staff had experienced harassment, bullying or sexual assault.

The apology marked a rocky start to an election year for Morrison and came as anti-vaccination protesters gathered outside parliament and his conservative party faced ructions over a religious freedom bill.

An election must be held by May, leaving few parliament sitting days before the federal budget is delivered in March, which is likely to trigger the start of the official campaign.

As parliament sat for the first time in 2022 on Tuesday, a statement was read by the speaker apologizing for "an unacceptable history of workplace bullying, sexual harassment and sexual assault in parliamentary workplaces."

Brittany Higgins, who in 2021 went public with details of her alleged rape that sparked the review, watched from the public gallery as all party leaders pledged change.

"We are sorry, I am sorry to Miss Higgins for the terrible things that took place here," said Morrison, adding that a place that should have been safe "turned out to be a nightmare."

Morrison's personal integrity has been under attack with damaging leaks, including by Higgins, of historical text messages from state and Coalition partner leaders, including some labeling him a "liar."

Polls show Morrison has also been marked down by voters over his handling of the coronavirus pandemic.

Reuters