Questions about tax exclusions for Māori land prompted angry exchanges between the prime minister and National's leader Simon Bridges in Parliament this afternoon.
The government continues to face a volley of questions about its plans for tax changes, after the release of the Tax Working Group's final report.
Among other proposals, that recommended a broad capital gains tax, excluding the family home.
It also says collectively owned Māori assets could merit "specific treatment".
"Māori Freehold Land under Te Ture Whenua Māori Act could be excluded from any extension of the taxation of capital gains," the report recommended.
Mr Bridges questioned Jacinda Ardern about whether that was something the government would adopt.
The prime minister told the House the report also recommended engaging further with Māori, "to determine the most appropriate treatment of collectively owned Māori assets".
She questioned Mr Bridges' motivations for his line of questioning.
"Where exactly is he trying to go with this issue - where exactly?"
He then asked her specifically whether the government would exempt Māori from any capital gains tax imposed.
The Tax Working Group acknowledged it should be considered, Ms Ardern countered, but no decisions had been made.
Negotiations are continuing between Labour, New Zealand First and the Greens to come up with a tax package they can all support; that includes whether enabling legislation would in fact be passed this term.
A final government response can be expected some time in April.