Terminally ill to watch NSW dying debate

For many, the debate over assisted dying is purely political but not for Scott Riddle.

The father of three with stage four bowel cancer says the prospect of choosing how to die "is calming in what is otherwise a scary scenario".

The Voluntary Assisted Dying Bill will be debated in the NSW parliament this week with scores of terminally ill anxious to learn whether they'll be granted control of their own destiny.

Drafted by a group of cross-party MPs, the private members bill is expected to be debated in the Legislative Council on Thursday.

If passed it will provide patients 25 or older whose deaths are imminent and are in severe pain a choice to end their lives.

Two doctors and a psychiatrist or psychologist would also need to determine whether they're fit to do so.

Keeping a close eye on proceedings will be Ian McPhee, who has cutaneous T cell lymphoma and faces "heading to what is possibly quite an uncomfortable and distressing end of life".

Dr McPhee, who's undergone arduous treatment including a bone marrow transplant, argues the bill doesn't present people with a choice to live or die so much as how to die.

"The whole point of the conversation is to acknowledge that the end for some is extremely distressing," he said.

"That's the point of having end of life choice - to give oneself freedom from physical and existential suffering."

Nationals MP Trevor Khan, who introduced the bill to parliament, says most supporters of voluntary assisted dying have seen a bad death first hand.

"My father died a particularly long and difficult death over some three and a half years and there's no doubt that that's an influence," he told AAP.

While the bill has support from Liberal, National, Labor and Green MPs, the opposition is similarly diverse.

Neither Premier Gladys Berejiklian nor Opposition leader Luke Foley will support the bill if it makes it to the lower house.

"I personally find this a very difficult issue and there is no wrong or right answer," Ms Berejiklian told AAP.

Others have been stronger in their opposition including Treasurer Dominic Perrottet who the bill is akin to condoning suicide.

With a 50 per cent chance of survival, Mr Riddle intends living but wants to know that if he loses his battle, his death won't be distressing.

"I definitely don't want to die but this bill is designed for a group of people who have no choice - they are going to die - and it's about how they die," the 36-year-old said.