David Seymour has revealed he expects hundreds of people to choose euthanasia in the first year it is legalised.
The preliminary results of two referendums Kiwis voted in were released on Friday, with the majority of voters saying 'no' to cannabis but 'yes' to euthanasia.
Just over 65 percent of Kiwis want the End Of Life Choice Act to become law, and the special votes - the results of which are due to be released next week - are very unlikely to change the result.
ACT Party leader David Seymour, who was the architect of the Bill, told Newshub Nation on Saturday that he was delighted with the results.
"Let's just stop for a moment and say that this is a great day for all of New Zealand. We have become a more compassionate, humane society which treats those suffering badly at the end of their lives better with freedom under the law."
The End Of Life Choice Act will likely come into law in November 2021, and Seymour pointed to other countries where euthanasia is legal as a guide for how many Kiwis will likely choose to use it.
"If you look at the American states which have quite conservative laws it's under 0.5 percent of all people who die. In some more liberal jurisdictions - the Netherlands, Belgium - it's 3 or 4 percent of all people who die.
"I would say New Zealand will be more like Canada or Australia, somewhere in the middle, perhaps 1 or 2 percent of people who die each year will choose assisted dying. That means in the New Zealand context, somewhere in the low-to-mid-hundreds of people."
Seymour said he thought the 33.8 percent of Kiwis who voted 'no' in the euthanasia referendum, just over 815,000 people, had decided to for one of two reasons: either they are opposed to the concept or have anxiety some people will be forced and coerced into euthanasia.
"I think the main thing I would say to the people that have those concerns is I understand why you would," he said.
"When I first became interested in this cause and got involved with it five years ago I had the same concerns but I can assure you this law is watertight. It's been debated more heavily than any other piece of legislation that I'm aware of in New Zealand history, and the evidence from overseas is no other country which has introduced a law like this has ever gone back because fundamentally they are safe and they work."
He said people would be protected by the law and there was no reason to think people who are poor, lonely, vulnerable are more likely to access this law.
"If anything it's the opposite. I'm not saying that's good or bad but that's the evidence from overseas."
Seymour also agreed more needs to be done around palliative care funding, but said it's not an alternative to euthanasia. Instead, it's "complementary".
For now, the leader isn't focusing on any new major legislation.
"I'm taking it one day at a time," he said.
"I want to do more of this kind of work, I think it is important that we keep improving our laws along the principles of individual freedom and personal responsibility."