Judith Collins has declined to criticise Parliament's Speaker because it's against the rules, despite her boss accusing Trevor Mallard of protecting the Prime Minister against tough questioning.
"The Prime Minister wouldn't answer and Mr Mallard was trying to protect her," Simon Bridges said earlier this week, after he was asked to leave the House of Representatives.
Ms Collins told The AM Show on Friday it "looked like that", but she wouldn't comment further on accusations of bias against Mr Mallard.
"You know I have rules I have to comply with under the standing orders - actually, Trevor and I get on really well these days," she told host Duncan Garner.
"I think every Speaker has their own style, and he's always fair to me. Let's put it that way."
Mr Mallard has long been used by the Labour Party as a partisan attack dog. He only stood for re-election last year in the hope he'd be Speaker, giving up his electorate seat of Hutt South and running on the Labour list, saying that would make it easier to be impartial.
"Judith's smart enough and knows the rules enough that you cannot say in the chamber that the Speaker is biased and is coming to the rescue of a minister."
Otago University law professor Andrew Geddis says it would be "impossible" for a Speaker to run Parliament if they had to constantly deal with accusations of bias.
"It's the same basic logic that penalises a sports player who abuses a referee, or calls him a thief," he wrote for RNZ. "Even if the player believes this, they can't come out and say it because without general respect for the referee's calls the game simply cannot be played."
Those rules even cover the media and public - but Parliament's been advised against taking action unless it's truly warranted.
"It is well understood that the House is a place of robust debate and that all members (including the Speaker and other presiding officers) can expect public comment and criticism if their performance warrants it," a 2015 report into Parliament's powers stated.
Prof Geddis said it wouldn't reflect well on politicians if they took action against the media over criticism of the Speaker.
"In fact, it probably would be the quickest way to generate an outcry for Parliament's contempt powers to be radically curbed."
Watch the full panel with Judith Collins and Michael Wood above.
The AM Show with Duncan Garner, Amanda Gillies and Mark Richardson, weekdays 6-9am on RadioLIVE and streaming live to the rova app on Android and iPhone.