Maori voters have until Wednesday to decide whether they want to vote on the Maori or general roll.
Those who wish to change which roll they're on can only do so during the Maori Electoral Option - which happens every five years.
The number of people on the Maori roll will determine how many Maori electorate seats there are in Parliament.
The latest campaign opened in March - and preliminary results show 5200 people joined the Maori roll halfway through - most of them being new voters.
Nearly ten thousand more people would need to join it by Wednesday to be on par with the number of people who joined in the 2006 option - which saw no increase in Maori seats.
There have been seven Maori seats in Parliament since 2001.
The campaign results will be available on Monday.