The 2018 Māori Electoral Option has closed, bringing only 1200 more voters on to the Māori roll.
The number of Māori electorates has remained at seven for the past six general elections but according to an electoral roll expert that could drop by one after the Option result.
The Option ran from April 3 to August 2 and gave all enrolled voters of Māori descent the opportunity to be on the Māori roll or general roll.
At the end of the Option, 52.4 per cent of Māori voters were on the Māori roll and 47.6 per cent were on the general roll.
At the start of the Option period those figures were at 52.8 per cent and 47.2 per cent respectively.
There have been net increases of 1200 on the Māori roll and 4015 on the general roll.
These results, alongside the latest census data, will determine the number of Māori seats in Parliament.
Electoral roll expert Graeme Edgeler said there was a small chance the result could mean the numbers of Māori seats in Parliament could drop to six.
More voters were choosing to go on the general roll than the Māori roll, he said.
"The big change isn't at the Māori Option but just the general enrolment pattern that Māori particularly young Māori or Māori who are enrolling for the first time - a lot of them are choosing to go on the general roll," he said.
"It has changed quite a bit since the last Māori Option.
"I think they will still make seven seats overall, but it's close."
But some factors could still have a boosting effect.
"The Māori population is growing faster than the non-Māori population, so if that continues that could see the number of seats go up."
National Manager for Enrolment and Community Engagement Mandy Bohté said about 95 per cent of Māori voters chose to stay on the roll they were already on and there was a small change in the proportion of voters on each roll.
"Of those who opted to change rolls, more moved from the Māori roll to the general roll, and when it came to new enrolments, more opted for the Māori roll," Bohté said.
Recently, Act leader David Seymour unveiled his Smaller Government Bill which proposes to scrap the Māori seats.
Seymour said he thought Māori seats had outsold their use by date and Māori were being over-represented in Parliament - calling the seven Māori MPs "hopeless".