Te Pāti Māori is attacking the government's assertion that requiring local councils to poll residents on whether they want Māori wards is democratic.
And one of the party's MPs has claimed MPs in the government of Māori descent who supported the bill have "internalised" racism against their own people.
The coalition government's Local government (Electoral Legislation and Māori Wards and Māori Constituencies) Amendment Bill passed its third reading on Tuesday.
The new law will require councils that brought in Māori wards without polling residents to hold one, or scrap the ones they had set up.
Speaking in Parliament, Local government Minister Simeon Brown said "divisive changes" were introduced by the previous Labour government that "denied" local communities the ability to determine whether to establish local Māori wards in their communities.
"They took away the voices of local communities across the country and undermined the principles of democracy," he said. "Today is a great day for local democracy."
But Te Pāti Māori MP Mariameno Kapa-Kinigi told Morning Report it felt like the government only supported democracy when it suited them.
"How come rural boards aren't being attacked? You see, so it's democracy when it suits, in our experience and in our view. So that's absolutely why we as a party absolutely object."
The Labour Party used the same argument when it, as government, abolished the need for a referendum for Māori wards. They argued no other types of wards, such as rural wards, went to a vote, a view repeated by leader Chris Hipkins on Wednesday.
"Under the previous law, prior to 2021 and now reinstated, Māori are treated differently to non-Māori in New Zealand and I don't think that's right.
"If a council can establish a rural ward or disestablish wards altogether and go to at-large council elections, that's not subject to a referendum. So why should the establishment or disestablishment of a Māori ward be treated differently to every other ward?
"This is a question of Māori being treated differently. We remedied that so that they weren't - they were subject to the same provisions as everybody else. And this government have gone back and said, 'No, no, it's got to be different when it comes to Māori.' I don't think that's justified."
Hipkins said Māori were not advantaged with "extra votes" with their own wards.
"There's still one person, one vote. They can either vote in a Māori ward or in a general ward. They don't get to vote twice. I think it's just about making sure that everybody's treated equally."
The bill came out of a commitment in the coalition agreements with both ACT and NZ First, both of which have Māori MPs, as does National.
'Internalised the racism'
Speaking to Morning Report on Wednesday, Te Pāti Māori MP Mariameno Kapa-Kingi said the benefits of having Māori representation in local government were obvious.
"[Māori wards have proven to be] a very good thing across the country… it's worked really, really well. The number of mayors, the number of submissions that came that I sat in on, were overwhelmingly in support of it - overwhelmingly."
James Meager, National MP for Rangitata, supported the bill in its third reading.
"One of the themes that comes across from the members opposite is that they believe that they have the single dictate, that they have the one true idea in the world on what it is to be Māori, on what it is to count as a Māori, and what it is to have your view count as being one that is of Māori world view," he told the House.
"They are the ones that get to decide; they are the ones that, apparently, hold all the cards. If you don't look like them, if you don't talk like them, if you don't walk like them, if you don't think like them, then you don't count.
"So here's a message to the tens of thousands of individuals - of children, of young people, of workers - out there in New Zealand who identify, who whakapapa Māori, who don't look like them, who don't think like them, who don't share their world view, and who they think don't count. Well, those people do count, and we share the view that their individual views count… We support people regardless of ethnicity, regardless of race, gender, creed, who can think independently.
"This bill does one very simple thing: it restores the rights for local communities to have a say on the creation of Māori wards - a special ward created by statute. It is only right that locals have a say on the creation of those wards. I commend the bill to the House."
Kapa-Kingi said whakapapa was "a special and important thing", but Meager's views came from "an internalised racist view", mentioning that his "boss" - presumably Prime Minister Christopher Luxon - was pākehā.
"When you've internalised the racism so deeply, that's what you sound like - you talk like he talks. So he can't help himself. you see? … He, like many in the coalition, that's how they talk, that's how they see the world because they're comforted by it and they're privileged by it…
"He's internalised the racism. He cannot help himself."
Asked for a response, Meager declined.
"I'll let Mariameno's comments speak for themselves," he told RNZ. "I'd rather be talking about things that matter to my electorate, not whether I hate myself."