Tasmania's Premier plans to push ahead with a bill to legalise voluntary euthanasia despite suggestions she does not have the numbers to see it passed.

Lara Giddings and Greens Leader Nick McKim aim to introduce their private members bill to parliament later this year.

Ms Giddings says a change to the law will create certainty for doctors.

"[Certainty] around some of the treatment they provide to patients or patient care, I should say, that they provide in the last stages of the dying process."

Speaker Michael Polley has confirmed he will vote against the bill and believes other Labor MPs are likely too as well.

Ms Giddings says 80 per cent of the population want to see change happen.

"I know there are people who want this legislation through," she said.

"They deserve the opportunity to have it debated in parliament, they deserve the opportunity to be able to lobby their elected members of parliament and they deserve the opportunity to be able to see where their elected members stand on these issues."

Australian Medical Association southern chairman, Dr Gerard McGushin, has backed comments made by the state president last week, who likened the legislation to state-sanctioned murder.

"It's state-sanctioned killing, or state-sanctioned homicide," he said.

"If you look up the dictionary definition of murder, it fits that criteria of intentionally killing.

"I understand that in layman's terms murder is a little bit emotive so if people want to not call it murder that's fine, but still recognise what it is, which is state sanctioned killing."