UPDATED 1.40pm Parliament will debate legalising voluntary euthanasia after Act Party leader David Seymour's private member's bill was drawn from the ballot today.

The controversial bill represents the best chance for voluntary euthanasia to be legalised in New Zealand - although the issue is deeply polarising and many MPs including Prime Minister Bill English are firmly opposed.

Despite opinion polls showing strong public support for legalising euthanasia, the issue's extreme divisiveness has meant politicians have been reluctant to champion a change.

That has all changed now Seymour's bill has been drawn from the lottery of a ballot.

His The End of Life Choice Bill is based on an earlier piece of legislation drafted by former Labour MP Maryan Street.

It would allow mentally competent New Zealand adults who have a terminal illness likely to end their life within six months, or have a grievous and irremediable medical condition, the choice to ask a doctor to help end their life at the time of their choosing.

The Director-General of Health would establish a group of medical practitioners who would maintain a register of health professionals willing to participate in assisted dying.

A new process would require two medical practitioners to be satisfied a person meets the required criteria. The second would be independent of the patient and initial doctor.

Seymour said today he was delighted the bill had been pulled from the ballot.

"This is morally, democratically and legally the right thing for Parliament to do."

He said he expected it to pass the first reading. His survey of MPs had 40 in favour, 27 against and the rest undecided.

"I think we will easily pass this legislation. Its time has come."

That confidence is based on conversations with MPs in Parliament's corridors, researching public statements, and pressure from voters (Seymour polled Epsom before putting up his bill and 69 per cent were in favour).

It was unlikely that the bill would be passed before the election, Seymour said.

He acknowledged the public fears around the issue, but said the bill had a range of safeguards. It would not allow mental health patients to choose euthanasia, he said,

A parliamentary inquiry into voluntary euthanasia began last year.

But that is unlikely to lead to a recommendation legislation be introduced and Seymour said he did not want to wait for the outcome of the inquiry.

The inquiry was prompted by a petition which followed the death of Wellington lawyer Lecretia Seales, who unsuccessfully sought a High Court ruling that would have allowed her doctor to help her die without criminal prosecution.

Matt Vickers, the husband of Ms Seales, said she would be "over the moon" about that Parliament would now debate the issue.

Lobby groups on both sides of the debate in New Zealand have become increasingly vocal, accusing each other of fear-mongering and spreading misinformation.