Malcolm Turnbull has backed Jobs Minister Michaelia Cash, saying she was being “bullied and provoked” when she threatened to out “young women” in Bill Shorten’s office.

Under pressure to apologise, Senator Cash “unreservedly” withdrew her comments on Thursday, but stopped short of saying sorry.

Mr Shorten, who said earlier on Thursday that he and his staff were still waiting to hear from Senator Cash, asked the Prime Minister if he would direct the Jobs Minister to formally say sorry.

Mr Turnbull told question time his Minister was “being bullied and provoked by Senator [Doug] Cameron who was making insinuations about staff”.

“She made a response which she has unreservedly withdrawn.”

Senator Cash, who threatened to name “young women” working for Mr Shorten who were the subject of “rumours”, had in fact offered a qualified withdrawal on Wednesday.

Claiming Senator Cameron was “nothing more than a bully”, she did not offer an apology when she fronted a Senate estimates hearing on Thursday afternoon, although she did “unreservedly” withdraw her comments.

The Jobs Minister also appeared to take cover – literally – in Parliament House, with security guards holding a whiteboard to block journalists’ view of the senator entering the hearing rooms.

Parliament House security has used a whiteboard to block cameras capturing @SenatorCash arriving at another Senate Estimates hearing. #AusPol #9News pic.twitter.com/ib8ViKy5A5

— 9News Australia (@9NewsAUS) March 1, 2018

It meant camera crews could not get a clear shot of the Jobs Minister, making for a spectacle of farcical proportions instead.

Media are allowed to film from the Mural Hall, a large open area in the centre of Parliament, but must not use their cameras in committee room corridors.

Mr Shorten released a statement just before question time on Thursday saying he was furious about the controversy.

“Of course I’m angry. I’m angry on behalf of the smart, dedicated, hard-working professionals in my office who have been smeared by Michaelia Cash,” he said.

I’m honestly shocked she hasn’t said sorry. I’ve been waiting for her to ring up my office and organise it.”

Labor’s Senator Cameron, who had been asking Senator Cash about staff movements in her office, dismissed suggestions he was casting aspersions on her staff.

“Anyone that knows me knows that I don’t do that type of thing, I mean it’s not of any interest to me,” he told Sky News.

Labor has called for Senator Cash to resign as result of her comments on Wednesday and for her office’s involvement in the leak of information about a raid on the AWU offices last year, which Senator Cameron had been pursuing in Senate Estimates.

Home Affairs Minister Peter Dutton escalated the public spat on Thursday, saying the Coalition refused to be “lectured” by Tony Burke and Bill Shorten when “people know that there’s a history of problems” in their personal lives.

Senior Labor figures including Mr Shorten and Mr Burke were careful not to criticise Barnaby Joyce over his extramarital affair, instead attacking him over the alleged misuse of public money.

Meanwhile, Victorian Senator Kim Carr was also slammed for suggesting in a separate Estimates hearing that Liberal Senator James Paterson was a member of “Hitler Youth”.

“If you took offence, I withdraw it,” he said, accusing Senator Paterson of earlier “throwing a bucket of shit” at him.

As Senator Carr mused about the French Revolution, Senator Paterson made a joke linking him to the Russian Revolution.

The Liberal senator said he would have been willing to withdraw his remark, but described Senator Carr’s response as “outrageous and “seriously offensive”.

“It’s extremely demeaning to survivors of the Holocaust and to their descendants, it diminishes their experience,” he later told Sky News.

“For all the political insults we throw at each other, surely that’s one we can leave aside.”