SOUTH Australians could choose voluntary euthanasia as an option in their living will in the event they develop an "intolerable" condition or disease later in life.

State Labor backbencher Steph Key is working on new voluntary euthanasia legislation and will meet with interest groups at the end of this month.

While she stressed she was still finalising her plans, Ms Key said she would prefer the option of voluntary euthanasia outlined in a living will, as is done in Belgium, to other models in places like Switzerland or Oregon in the US that require the patient to carry out or administer euthanasia themselves.

A living will allows a person to take control of end-of-life medical decisions by indicating if they would prefer or refuse treatment for future illnesses.

Under Ms Key's preferred model, a person would be able to state in a will that if they find themselves in "a situation where their life is intolerable in a medical sense then . . . they would like to follow through with the option of voluntary euthanasia".

"That doesn't mean that you have to follow through with that necessarily or you can't change your mind," Ms Key said.

However, she said the decision should be made before a person became too sick.

"In some places you can make that decision when you're actually on you're death bed (but) it's hard to know what someone's view is if they're (too far) gone or they can't communicate."

A government Bill to simplify the process of making a living will is before Parliament but it rules out medical choices that are illegal, such as voluntary euthanasia.

Ms Key said she had not decided whether she would introduce a new Bill or draft amendments to existing law.

University researcher and SA Voluntary Euthanasia Society member Julia Anaf said there had been a "paradigm shift" in young people's thinking about the issue. "Their comments are 'I've just seen my gran die and there's no way that's going to happen to me'," she said.