National Party MPs have stopped singing from the same song sheet on whether Māori should be allowed to switch electoral rolls at any time.
Māori can only change rolls every five or six years when the Māori Electoral Option comes up - but there have been renewed calls from frustrated Māori who have been prevented from changing rolls ahead of 19 September.
The electoral commission also supports a law change to allow Māori to be able to change rolls at anytime, which was put to the Justice Select Committee after the last election but did not make it through because the National Party opposed it.
National List MP Jo Hayes has called for her party to change its position.
"It's a choice thing... and there comes times like this particular election where we're getting more pushback from Māori on the Māori roll saying they don't have a choice and they'd like the option to move across," Hayes said.
National Party spokesperson for electoral reform Nick Smith doubled down on his position that the law should remain the same, and said Māori were privileged to have the choice.
"I think it is a privilege because it is a right that other voters don't have - other voters must be in the electorate of which they geographically live," he said.
"I think for practical reasons and the integrity of the electoral system the five-year rule about when they exercise that, actually is fair."
Smith said the Electoral Commission were unable to say, when the law change proposal came up at the Justice Select Committee, how they would prevent political parties "manipulating" the system.
A spokesperson for the electoral commission said they were aware that greater flexibility would allow some individuals to vote strategically by switching rolls.
"However, we think the greater flexibility this choice would offer Māori voters generally is more important.
"It would be for Parliament to decide whether to act on our recommendation and make a law change [and] such an amendment could address the question of whether to limit switching back and forth between rolls".
Justice Minister Andrew Little signalled he wanted a wider review of the electoral process, including the Māori electoral option.
He is in favour of Māori being able to change at any time, but admitted there was still more work to do to ensure it would not impact on the integrity of the electoral system.
"I think it can be dealt with by writing the rules fairly, so you can put some constraints around it."
"The reality is the National Party have a track record of trying to make it harder for some people to vote, so I don't subscribe to their view and their view of the world that it's all about people trying to manipulate things."