Parliament's Speaker, Trevor Mallard, has an inbuilt bias against National Party leader Simon Bridges and a soft spot for Prime Minister Jacinda Ardern.
That much has been clear since Mallard took the chair just over a year ago. Bridges gets under his skin.
But what is also clear is that Bridges crossed a line in the House today and cannot credibly object to having been thrown out by Mallard.
If the incident forces Mallard to reassess the way he is trying to control the House, it may be a good thing.
It was during questions to the Government about the Karel Sroubek case that Bridges accused Prime Minister Jacinda Ardern of "ducking and diving".
Such a description is not unusual in the cut and thrust of politics, and barely raised anybody's eyebrow – except Mallard's.
Mallard stood up to object – we don't know whether he was about to make Bridges withdraw and apologise and put him on a final warning.
But before he could mete out punishment, Bridges said: "Here comes the protection."
That was the offending phrase and that got him ejected from the House – and for that there can be no objection.
It crossed a line. It can be easily argued that Mallard was too quick to leap to the defence of Ardern after she was accused of ducking and diving – not that she requires any help from Mallard in the chamber.
But for Bridges to accuse the Speaker of protecting the Prime Minister is an unacceptable insult.
Allegations of bias against the Speaker are usually expressed more obliquely through eloquent points of order by Shadow leader of the House Gerry Brownlee.
After Mallard had ordered Bridges out, Brownlee interjected that it must have struck a nerve, and Mallard ordered Brownlee out too, creating a walk-out of most MPs except those which had questions to ask.
It was not an isolated incident. National has long objected to Mallard's unfair practice of taking questions off National as a punishment for a transgression.
He did it yesterday when Melissa Lee and Louise Upston sighed during a ruling from Mallard - after first making them stand and apologise.
For as long as that egregious rule is applied, there will be wounded relations between the Speaker and the Opposition because that is the Speaker playing God.
Mallard's intolerance was on display yesterday when he referred to Bridges' questions as "smart-arse" which is also an appalling lapse by a Speaker to the Leader of the Opposition.
And during an exchange with Brownlee, he basically agreed that tighter standards apply to Opposition questions than to answers by Government Ministers.
He can't stand a bit of cross-house banter and he seemed personally offended when MPs interject in the second person.
The sadness of Mallard's speakership is that he had hopes of inserting himself less into Question Time than other Speakers, but he is doing the exact opposite.
On Newshub this week, Winston Peters tried to suggest that Mallard was not behaving like a Labour MP, but that is not true. It is impossible to take the politics out of the politician.
And the other part of Mallard's problem is that he knows standing orders better than any other MP – or any other Speaker for that matter.
He runs the House in a way that he expects everyone else does as well, which makes for an intolerant Speaker.
On a good day, when he is in a good mood and does not expect perfection, when he is in a mood to help the Opposition hold the Government to account, Mallard is the best of Speakers.
His stewardship of the House as the Opposition sought answers from the Government over its decision to exempt Te Arai Development from the Overseas Investment Amendment Bill was exemplary.
The stakes were high. He bent over backwards to be fair to all. It was the House at its best because Mallard was at his best.
Unfortunately, the good days don't come often enough.