Justice Minister Paul Goldsmith says very few countries allow voters to enrol on election day, and New Zealand should consider changing the rules.
A report by the auditor-general released on Tuesday found an unprecedented number of special votes were cast in last year's general election, leading to rushed final checks and mistakes.
"It's really difficult to forecast how many special votes we would get," chief electoral officer Karl Le Quesne told Morning Report on Wednesday.
"Normally, we'd look back at what the trend was in past elections, but 2020 was a really unusual election with the change in date. We had a lot more time to enrol people when the election date was shifted out.
"We did forecast there would be more special votes and enrolments during voting, but it turned out to be much higher than what we forecast."
Listen to the full interview with Karl Le Quesne
The 2020 election was delayed from September to October due to an outbreak of Covid-19 in Auckland.
That same year, the rules were changed to allow people to enrol to vote as late as election day, then-justice minister Andrew Little saying about 19,000 voters were "disenfranchised" in 2017 due to their details not being up to date.
"Special votes in enrolments or enrolment updates while voting can take up to 10 times longer to process, and that's what put us under so much pressure during the official count," Le Quesne said.
None of the mistakes, once fixed, had any effect on the outcome in any electorate or the overall result.
Le Quesne said it was "a matter for Parliament to consider and decide" whether same-day enrolments should be canned, but it would make the Electoral Commission's job easier without having to hire "a few hundred more people".
Paul Goldsmith, the current justice minister, was keeping an open mind.
"There's some basic, basic stuff that the auditor-general pointed out, so we're obviously concerned about that, and I will be making my expectations absolutely clear to the Electoral Commission around performance. So that's absolutely the case," he told Morning Report.
Listen to Justice Minister Paul Goldsmith
"The broader question though is whether the design of the system, particularly with the same-day enrolments - enrolments on election day, which is … a new idea - is adding much more pressure to the system.
"And remember that they used to be out of count everything in two weeks. This time, they were in a mad rush to count it in three weeks. We were waiting and waiting and waiting and still mistakes were made. And so that's the issue."
Goldsmith said it already cost $227 million to run an election.
"Rather than, you know, just throw even more hundreds of millions at the problem, wouldn't it be more sensible to ask, have we overcomplicated? Have we made it too, too complicated? Can we simplify it in some way?"
Listen to the interview with Chris Hipkins
Labour Party leader Chris Hipkins said the Electoral Commission should make sure the system ran smoothly and "taking away the right of thousands of people to vote" was not the answer.
"Thousands of people enroled and voted on the day. If they're saying they'll stop that happening they're basically saying that thousands of people won't have their vote counted.
He said the commission was given extra funding for 2023 but it was not at the same level as they were given in 2020 to run an election in the midst of a global pandemic.
Special votes typically favour Labour and the Greens, who commonly pick up seats in the final results compared to what was counted on the night, at the expense of National.
For example, in 2023 the Greens picked up one extra seat and Te Pāti Māori two, while National lost two. In 2020, Labour and Te Pāti Māori each picked up an extra seat, while National lost two.
Goldsmith said he would wait for the Electoral Commission's own report and send it to select committee before the government made any decisions. He said the Labour-led government "didn't try to be very bipartisan" when it made changes to voting enrolment.
"Look, we'll work our way through it. What happens is I get the formal report, then it goes off to a select committee and then the government makes decisions about whether it's going to make any changes or not. And so there'll be plenty of opportunity for people to have their say."