Shane Jones was forced to apologise for yelling "Ngāti Epsom" at Paul Goldsmith - who National leader deputy Nikki Kaye incorrectly said was Māori - as he rose to speak in Parliament.
The Northland-based New Zealand First MP was ordered to retract the quip, with House Speaker Trevor Mallard saying that "the relatively senior member from the North should know better."
"This is a matter that's had some publicity," Mallard said.
• National leader Todd Muller slams three Labour MPs for 'abject failure' in government
• 'Once a peacock, now a feather duster': Ousted National leader Simon Bridges reveals plans and disappointment
• Deposed National deputy Paula Bennett opens up: 'Friday was a pretty brutal day'
• National leader Todd Muller's new caucus: Amy Adams returns, Simon Bridges staying on
"It's an error made by a member of Parliament and my view is that it should be left there," Mallard said.
The error the speaker was referring to was the earlier blunder made by the National leader and his deputy, who suggested Paul Goldsmith was Māori when defending the diversity of their shadow cabinet.
Talking to reporters before going into their first caucus, deputy leader Nikki Kaye said the Epsom-based Goldsmith Ngati Porou when he is not.
Kaye then said the National Party had three Māori in their shadow cabinet: Goldsmith at No 5, Paula Bennett at No 13 and Shane Reti at No 17.
Muller then confirmed in answer to a question that Goldsmith was the only Māori in the party's top 12.
Goldsmith then said that while he had lots of relatives who were Māori – his great-great-grandfather had European and Māori wives – he himself was not Māori.
"I make it quite clear. I am not Māori myself. The Goldsmith family have many connections to Ngāti Porou. My great-great grandfather had European wives and Māori wives so I've got lots of relatives across the Ngāti Porou but I don't claim to be Māori myself."
Asked why the leadership would be suggesting he reflected diversity on National's front bench, Goldsmith said: "Well, that's for them to explain. In terms of the broader context, I have lots of Māori connections with my family, personally I'm not directly Māori."
Winston Peters defended Jones' comment after the apology, saying that it was "not a matter of racism".
It was important "for anyone in this country who's been here and has ancestry of a thousand years who is Māori, that people are actually identified to be either that or not", Peters said.
"I think it's a legitimate thing to raise in this house, when someone has the ignorance to say that someone else is Māori, and that person himself says he's not.
"I think sorting it out in this house is pretty important."
While the topic "might be of some embarrassment", Peters said that was no reason to avoid the "silliness" he'd seen in other countries such as when President Donald Trump called US Senator Elizabeth Warren "Pocahontas" in 2016, after she claimed Cherokee and Delaware Indian heritage.
"If it's still drumming around in the American political system, surely we can have our day of fun," Peters said.
Mallard answered that he was sure that later in the afternoon, "when we get into a debate, there will be an opportunity for something that is slightly wider".
Muller earlier said that he appreciated that some would see his reshuffle yesterday from a perspective of the front bench and shadow cabinet.
"But I looked at it across the whole 55 and particularly those who I gave significant jobs to and the message I will be imparting shortly in my caucus room is that we collectively now have a huge job to do including across the caucus. They have significant roles and I will be looking as I come to a final conclusion post-September upon winning the election and pulling together a cabinet as to who I would like ultimately sitting around the table based on talent, workload, effort and capability."