Euthanasia referendum: Why cancer campaigner Melissa Vining is undecided on the End of Life Choice Act

Southland's Melissa Vining has revealed why she's undecided on the proposed euthanasia law, saying she has concerns around some aspects of the Bill.

Vining's husband, cancer care campaigner Blair Vining, died of bowel cancer last year and dedicated his final days campaigning to reform the way the illness is treated and pushing for equal care for sufferers throughout New Zealand.

That work has been carried on by Melissa. Her and Blair's Southland Charity Hospital - one of his dying wishes - opened in May.

Melissa, who partook in Three's euthanasia discussion on Wednesday night, said while she supports people having a choice, she's concerned Blair could have chosen to end his life without telling her.

"The fact that when Blair was diagnosed, he was given 6-8 weeks to live and we had many, many great memories where he lived longer," she told host Patrick Gower.

"He didn't want to die but he wouldn't have gone and done it behind my back because he didn't love me or because we had a dysfunctional relationship - he would have been trying to save me.

"There's 4500 people begging for their lives right now because there is no money to treat them - that's not a small number [and] that's just for cancer."

Former Prime Minister Sir John Key, who has thrown his support behind the referendum, said the law has an "enormous" number of safeguards.

"[For] the person to actually be able to apply the law has to be dying - this isn't about someone who says, 'I want to opt-out of life' or 'I don't want to let it run its natural course'. This is about someone that is dying and at the very last piece of that, they are choosing the time of their death."

Hospice NZ clinical adviser Rod MacLeod, who's against the referendum, believes the majority of palliative care specialists are too.

He said that was telling, "because they're the ones who do this - day in day out. I looked after people for 30 years - and if I was to be put in a position to enable somebody to take their own life, I would find that astonishingly difficult."

MacLeod said doctors don't have enough education about palliative care.

"Our medical students come out after six years in medical school having had, maybe, three or four days of teaching about the end of life care - if they're lucky, they'd have had a day at a hospice.

"In their first year [as doctors] they're going to have to, on average, look after 40 people who are dying. Would you like somebody to look after you who'd had three or four days of training in your last weeks or months?"

The End of Life Choice Act will become law should more than 50 percent of voters tick 'yes' at Saturday's election, as the referendum is binding.