Their advocacy for euthanasia is based on ending pain and suffering when there is nothing left to live for, and on human dignity - a person's right to determine their fate and leave the embarrassment of helplessness, incontinence etc behind.
On the other side of the coin, opponents have argued that acceptance of assisted suicide will make it a more likely option at the expense of quality palliative care and that some people are euthanised without even asking for such an ending.
Mercy killing is illegal in New Zealand, and don't expect any change soon - there are few votes to be gained for any government passing such legislation. And, certainly, should any euthanasia law be passed, it would have to be utterly rigorous and replete with caveats and conditions to protect the vulnerable from any possible abuse. But experience tells us there are times when a peaceful, painless, medically-controlled farewell is what the patient wants and deserves. Should they be denied?