Election law expert Graeme Edgeler says this is partly to do with the reasons why people cast special votes.
People who were not enrolled on election day or needed to update their details would have cast a special vote. Students, for example, who were often left-leaning, might not keep their enrolment details updated given the transient nature of flatting, Edgeler said.
“Given the number of special votes this election - the most ever - my guess is probably National loses two. One or two, would be my guess... based on the fact every election since we have had the current rules around specials, it’s been one or two.”
In 2017, there were 419,669 special votes - which is 16.2 per cent of the vote. By the time the official result was declared, National’s initial seat allocation was reduced by two while Labour and the Greens both gained one seat each.
In the 2020 election, 493,967 people cast valid special votes - accounting for around 17.1 per cent of the total vote count. Once again, special votes leaned left and after they were included in the final count, National had two fewer seats than the election night result predicted.
The left/right distribution of votes on election night in 2017 and 2023 is very similar. This may mean that the make-up of the 2017 specials is more predictive of this year’s specials than 2020.
If the percentage difference between election night and special votes is the same as in 2017 and Te Pāti Māori don’t win another seat, then National will have three fewer seats than the election-night result predicted, and Labour and the Greens will each pick up a seat.
If the 2020 differences play out then National will drop two seats and Labour will pick up one.
Using the percentage difference between election night and special votes in either 2017 or 2020 predicts that once all votes are counted, National and Act will not have enough seats to govern alone.
Electoral law changes in the last decade have made it easier for New Zealanders to vote. People used to be required to have a special reason to cast an early vote, or had to be enrolled before election day.
Today, anyone eligible can vote from anywhere in New Zealand during the voting period - whether they are enrolled or not. Edgeler says this is the reason why it takes the Electoral Commission around three weeks to count the vote.
“Why does counting the special vote take so long? In short, because we make voting easy in New Zealand,” he says.
“We made a choice as a country... that you should be able to vote anywhere in the country on election day itself and at any embassy or High Commission in the world on the day before - simply by rocking up and asking for voting papers and a form.”