The Māori Party is accusing National of inciting "political division" and "racism" over its opposition to iwi checkpoints set up across New Zealand amid the COVID-19 pandemic.
Those operating the checkpoints say they are concerned by the number of people continuing to travel between regions under alert level 3, and Police Commissioner Andrew Coster says they are perfectly legal.
But National MPs, including leader Simon Bridges, say the checkpoints are illegal, that they impede freedom of movement, and are accusing police of turning a blind eye.
"They're unlawful, aren't they?" Bridges asked Coster during a grilling by the Epidemic Response Committee on Thursday.
The Police Commissioner assured Bridges the checkpoints "are not unlawful" and that the police "are operating within the law".
Māori Party co-leader and Taranaki iwi leader Deborah Ngarewa-Packer has been working the south Taranaki checkpoint and says since the move to alert level 3, two-thirds of drivers were breaking the rules.
"If we weren't doing this, and educating and passing on how they should be moving, who is going to?" Ngarewa-Packer told Newshub. "It's so concerning."
Those manning the checkpoints say they are educating the public and drivers aren't forced to stop.
Ngarewa-Packer said now is "really not the time for the Nats to use the pandemic to incite political division or racism".
Former police officer turned National MP Mark Mitchell went even further than Bridges, suggesting police are "getting pressure from the Government around these illegal checkpoints".
"Outrageous. That's a disgrace, Mark," Labour MP Ruth Dyson said, after Mitchell requested the names of those within the Government who had advised Coster on the issue.
Coster said he'd had "absolutely no influence" from the Government.
"The only minister I have spoken to is the Minister of Police [Stuart Nash], and that was me proactively briefing him... At no time has he given me a direction."
The Māori Party supported the previous National-led Government through a confidence and supply agreement but lost its presence in Parliament after the 2017 general election.
Bridges has talked about a resurgent Māori Party as a potential ally, but Māori Party President Che Wilson earlier this year indicated a strong preference for Labour.
"We're clear that our people align more to Labour and so we are open to having a conversation with Labour."
The Māori Party announced last year that Ngarewa-Packer will stand in the electorate of Te Tai Hauāuru for the 2020 general election.