Two weeks of ducking and weaving the forensic questioning of Shadow Attorney-General Mark Dreyfus, QC, has left Mal Brough weakened and his Prime Minister bruised by association.

The ALP has aimed a barrage of questions at Mr Brough over his involvement in the Peter Slipper affair, culminating early on Wednesday in a partial apology from the Special Minister of State for misleading parliament.

Prime Minister Malcolm Turnbull has stood by Mr Brough and fresh from the Paris climate talks provided his strongest defence yet.

“Guilt or innocence is not determined by public denunciation, here or anywhere else,” Mr Turnbull told parliament. 

• Ashby, Brough question editing of crucial Slipper affair interview
• Police raid James Ashby’s home over Slipper diary
• Mal Brough apologises over ‘disjointed’ answer

But the PM stopped short of offering his full confidence in the minister charged with protecting the integrity of the government.

Although Mr Brough has almost survived the final sitting week of the year (there’s one day left), the matter has been damaging for the government and may continue to be into the new year when police conclude their investigation.

Malcolm Turnbull defended Mal Brough, and said there was no new information to warrant further questioning. Photo: AAP

“You would have to think that eventually the damage would be too great and that Mal Brough will have to go,” Murdoch University senior lecturer Ian Cook told The New Daily. “But there is that complication of Malcolm Turnbull trying to appease that other [Abbott loyal] side of the party.

“Unless some other issue comes up … it is very hard to imagine Mal Brough hanging on.”

The current parliamentary debate centres on whether Mr Brough asked former staffer James Ashby to obtain copies of then-speaker Peter Slipper’s confidential diary in 2012.

Mr Dreyfus told ABC Radio that Mr Brough appeared to have “misled parliament” and “at the very least” should stand aside.

“I cannot remember the last time a serving minister in the government of the Commonwealth was the subject of a search warrant executed on his own house,” Mr Dreyfus said.

The ALP initiated a motion to strip Mr Brough of his ministerial appointments, including Special Minister of State, on Wednesday morning, but were gagged.

A similar motion, and defeat, followed in Question Time the same day.

On Monday, Mr Brough said an interview with Channel 9’s 60 Minutes had been selectively edited to change the context of a seemingly unequivocal confirmation he had asked for copies of Mr Slipper’s diary.

But this claim was undermined by the release of the official transcript – which proved the context had not been changed – and a contradictory answer to the same question in parliament on Wednesday.

Why is Labor calling for Brough’s resignation?

James Ashby reached a $50,000 settlement with the Commonwealth over his claims of failure to provide a safe workplace. Photo: ABC

Pressure on the Special Minister of State escalated after Australian Federal Police searched Mr Brough’s home on Queensland’s Sunshine Coast on November 17.

Under the same warrant they attended the Beerwah home of former Slipper staffer, Mr Ashby.

The AFP were looking for information on the sharing of notes from Mr Slipper’s parliamentary diary, which was allegedly copied by Mr Ashby, without authorisation, and sent to Mr Brough in March 2012.

In the same year, Mr Ashby launched legal action against Mr Slipper, alleging sexual harassment – the charges were later dropped – while the former Speaker won a 2015 appeal against a finding of guilty in the misuse of more than $900 of taxpayer-funded Cabcharges.

“We have got an instance where someone has asked the staffer of a minister to divulge elements that would otherwise be confidential,” Dr Cook said.

“There are some issues, particularly around what James Ashby was asked to do, which, potentially, someone has been asked to commit a breach, if not of law, at least of morality.”

Brough ‘quite a big scalp’

The PM’s polling honeymoon could be over. Photo: Getty

Electoral analyst William Bowe said next week’s polls would be interesting “for the first time in a while”.

But he thought the Brough saga would not influence a potential change, but a perception of “disunity” within the party and those loyal to Tony Abbott.

Backbench MP Wyatt Roy has also been named as involved in the Slipper affair, but the ALP is probably unlikely to pursue him.

“Mal Brough has been such a major figure in Australian politics for some time now, so I guess, he is quite a big scalp, in a way that Wyatt Roy is not so much,” Dr Cook said.

Thursday is the final day in the 2015 parliamentary sitting calendar before an extended Christmas break.