David Seymour is confident his voluntary euthanasia bill will be passed by Parliament, but the final vote could be more than a year away.
The ACT leader's End of Life Choice Bill was drawn from the ballot last week and will go on the Parliament's agenda for a first reading.
MPs will cast conscience votes on it, and parties won't take positions.
Mr Seymour last ran the numbers on his bill six months ago - he says there were 40 MPs in favour, 27 opposed and about 50 who hadn't made up their minds or wouldn't tell him how they would vote.
"We have convinced a third of them, and I think we will convince more than a majority - I think we are easily going to pass this legislation," he said.