With a parliamentary committee due to table its report on David Seymour's euthanasia bill on Tuesday, the Act leader is "quietly confident" about its future.
The Justice committee received around 38,000 submissions on Seymour's End of Life Choice private member's bill. The majority of them were opposed to assisted dying, according to one lobby group which analysed them.
"This is something that is becoming increasingly normal around the world and something that New Zealanders overwhelmingly want," Seymour told the Herald.
"However, as we can see from the select committee process, we face a very well-orchestrated campaign from a motivated minority who are extremely committed to defeating the bill," he said.
The bill as it stands would give people with a terminal illness or a "grievous and irremediable medical condition" the option of requesting assisted dying.
"It allows people who so choose, and are eligible under this bill, to end their lives in peace and dignity, surrounded by loved ones."
There has been some high-profile opposition to the bill, including former prime minister Sir Bill English and his wife Lady Mary, a Wellington GP. Former Māori Party co-leader and disability issues minister Dame Tariana Turia has also spoken out against it.
But speaking ahead of the report's public release on Tuesday, ahead of the bill's second reading, Seymour said he was "quietly confident" of its future.
In December last year Seymour recommended changes to his bill that sought to put the best possible version forward to the Justice Committee to ensure it got through its second reading.
He recommended a binding referendum at the next election, limiting eligibility to the terminally ill, clarifying that access cannot be by reason of mental health conditions and disability only, and incorporating the Access to Palliative Care Bill sponsored by National MP Maggie Barry.
Seymour said he hoped the committee had made the changes he had urged but "if it transpires that they haven't then I will be putting up supplementary orders at committee stage to put in place the changes that my sponsor's report recommended".
The Care Alliance analysed almost all of the submissions made on the bill and found 90.2 per cent opposed it, 8.1 per cent were in favour and 1.7 per cent were neutral or unclear.
The Care Alliance's members include the Catholic bishops' bioethics centre, the Salvation Army, Lutherans for Life, Hospice NZ and the Christian Medical Fellowship.