Prime Minister Jacinda Ardern gives Speaker Trevor Mallard grilling over behaviour in Parliament

Prime Minister Jacinda Ardern has given House Speaker Trevor Mallard a grilling over his behaviour in Parliament.

"The serious issue of alleged sexual assault and harassment at Parliament was poorly managed and inappropriately politicised last night. The tone of the debate did not reflect well on Parliament as a whole," Ardern said in a statement on Wednesday.

"Any investigation of claims of sexual assault should be in a manner that takes a victim-centric approach. It also needs to include principles of natural justice for the person allegations are made against."

Ardern said she spoke with Mallard on Wednesday morning.

"He retains my overall confidence; however I have expressed serious concerns to him about the manner in which he conducted himself in the House last night.

"It did not meet the standards I expect. Nor do I consider it to have met the needs of the victim in this situation. The Speaker acknowledges he did not meet his own standards either."

Ardern also slammed the Opposition's "inappropriate" behaviour.

"Issues of this serious nature should not be litigated in Parliament in such a manner. It was wrong. Parliament rightly needs to set standard for others to follow."

House Leader Chris Hipkins said on Tuesday he also planned to address the Speaker, after an explosive night in Parliament in which allegations of sexual assault were raised. 

"I sat through the debate last night. I don't think it reflected well on Parliament as a whole. I don't think it reflected well on pretty much anybody that was taking part in that debate."

Mallard came under fire in December last year after more than $300,000 in taxpayer money was spent to settle his legal battle with a former parliamentary staffer accused of sexual assault, which Mallard had described as tantamount to "rape".

Mallard made the comment after the Debbie Francis report into bullying and harassment at Parliament was made public in May 2019. He was commenting on the report's disclosure of sexual assault accusations in the report.

The Speaker apologised "unreservedly" for the accusation in December when speaking to the Governance and Administration Committee. He said he realised his mistake "probably within 24 hours" of making the original comments.

But on Tuesday night in Parliament he repeated sexual assault allegations under parliamentary privilege, pushing back on claims by National MP Chris Bishop he'd ruined the former staffer's life. 

"That man's life was destroyed when he sexually assaulted a woman. That's what did it," Mallard said. "I will support the woman and what she said, I will support the investigation that found that he seriously assaulted her... and I will support the police and their investigation and the results of that."

Ardern wants to take the debate back to what was at the heart of it: the Debbie Francis review.

"The Francis Review and its recommendations, including the introduction of specific Behavioural Standards for all who support the work of Parliament, offer a blueprint for best practice and I believe Parliament should be focused on that."

Ardern wants to reconvene he cross-party working group to consider how those standards can be used when MPs are dealing with sensitive staff conduct matters such as sexual assault.

"Parliament must continue to maintain its right to hold Government ministers and the Speaker to account for actions. However, this can be done in a robust and appropriate manner."

Mallard told Newshub he's prevented by court suppression order and mediation agreement from commenting outside the parliamentary process.