Speaker Trevor Mallard has apologised to all New Zealanders for his "mistake" which cost taxpayers $330,000 in legal costs.

While answering MPs questions at a select committee meeting this afternoon Mallard said he "clearly made an error" when he accused former Parliamentary staffer of being a rapist.

"My key regret is essentially a confusion of the law which led to this."

Mallard said he interpreted misconduct as rape "which it did not amount to rape".

"That's the confusion that I had and I regret that."

Mallard made the comments 18 months ago after the release of the Francis Review into bullying and harassment of staff at Parliament which found 14 reports of sexual assault.

The plaintiff sued Mallard for defamation and after settling the case in early December, Mallard last week issued a public apology to the man.

He later revealed the case cost taxpayers more than $330,000 - including a $158,000 payout to the plaintiff and more than $175,000 in lawyers fees.

"It is a lot of money that could have been better spent," Mallard told members of the committee.

Mallard said he wanted to appear before the Governance and Administration Select Committee because he cared "deeply" about Parliamentary accountability and transparency and ensured a clause was included in the settlement which allowed him to do so.

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The Speaker appeared alongside the chief executive of Parliamentary Services Rafael Gonzalez-Montero who confirmed the man was stood down soon after the Francis Review was released but that timing was co-incidental.

It was also revealed the man had also taken employment action against Parliamentary Services which had so far cost taxpayers about $37,000 in legal fees.

Shadow leader of the House, National MP Chris Bishop, questioned Mallard over the timing of his statement which was made the same day as the Royal Commission of Inquiry report into the Christchurch terror attacks.

Mallard said the settlement was agreed at 5pm on Thursday December 3 and he issued the statement on the next sitting day of the House, which happened to coincide with the inquiry report.

But out of respect for the victims he waited until later that day.

Bishop also questioned why Mallard had refused to make a comment about the settlement when asked about it in the House last week.

The Speaker said if he'd been given some notice he would have been "better prepared" and could have come to an arrangement consistent with the agreement and the carve-out clause.

Because it was the first time a Speaker had been sued, a process had to be established for who signs off the Speaker's legal costs.

Mallard said he delegated that to the then Deputy Speaker, National MP Anne Tolley, who sought advice from the Solicitor General. She decided a Speaker should be treated the same as a Minister which have all their legal costs and settlements covered by taxpayers if they're sued in the course of doing their jobs.

Mallard said he also did not think it was appropriate for the decision to go to Cabinet because of the Speaker's independence and because of concerns over political partiality.

"I obviously made a bad mistake at the beginning but I worked really hard not to compound that moving forward."

And on changing the Speaker's 'directions' so all MPs can have settlements covered by the taxpayer, Mallard said he recused himself from that decision and it was made by a cross-party group of MPs chaired by National MP Gerry Brownlee.

That process was separate to the one followed in Mallard's case as he is a Minister.

It was his understanding that decision was agreed to by all parties.

Mallard said his error about the comments had taken attention away from the work to make Parliament a better workplace and he regretted that.

"I made a mistake and for that I unreservedly apologise to the House and to New Zealanders."

Both National and the Act Party have said the revelations about the settlement have caused them to lose confidence in the Speaker and indicated they'd move a motion to that extent when the House resumes in February.

But given Labour's outright majority, the motion will not succeed.

Prime Minister Jacinda Ardern said on Monday she still had confidence in Mallard and that he continued to be the right person to do the job.

Mallard was asked about conversations he'd had with Ardern and said she'd never expressed that she'd lost any confidence in him.

The Taxpayers' Union pig, which had been sitting in on the meeting, was removed before MPs' questions began.

'Mallard should go'

After the select committee meeting, Act leader David Seymour issued a statement saying the "revelation" further proceedings were underway relating to the man who sued Mallard further showed he was unfit to be Speaker.

"How can a guy who behaves so poorly be the leading figure upholding democracy in New Zealand?

"Mr Mallard talks about protecting people who work in Parliament but the only person he's protecting is himself.

"Why does Jacinda Ardern keep protecting him?"

Seymour said if a minister made a similar mistake to Mallard they would be stood down or demoted.