That was the steely warning amid the jubilation on Friday from supporters of voluntary euthanasia for terminally ill Victorians; that this legislation is not a done deal.

The passage of the bill through the Victorian Parliament's lower house via a conscience vote is a huge achievement, particularly considering some had believed this is where it would face its greatest challenge. But it must still win a majority next month among the 40 members of the Legislative Council.

Shortly after the vote on Friday, Premier Daniel Andrews emerged from the chamber to tell reporters that he believed State Parliament had performed at its best on this issue. And its passage through the lower house was a major step towards giving Victorians the dignity and compassion they had been denied for "far too long".

But Mr Andrews was careful to avoid raising hopes or appearing confident that the bill would easily pass the upper house.

"I don't take anything for granted there," he said, from the steps of State Parliament.

Some voluntary euthanasia proponents have long-hoped they have the numbers, just, in the upper house and the real challenge was always to get the 44 votes it needed in the green chamber.

In the end, it came out with a clear majority of 47 to 37 on Friday morning, but not before a scare or two along the way.

Now a new set of challenges await. But Labor should have learned this week to expect the unexpected after being hit by a procedural ambush sprung by one of its own and surprised by the grit of the filibuster-like delaying tactics employed by opposition MPs.

Australian Conservatives MP Rachel Carling-Jenkins, whose seat is in the upper house, praised the efforts of members who had led the opposition to the bill in the lower house. But Dr Carling-Jenkins said she had no plans to move any amendments of her own.

"I think the bill needs to be defeated outright," she said.

Dr Carling-Jenkins, who is an outspoken opponent of the proposed laws, said it was "definitely no sure thing" the bill would have enough support to pass the upper house.

Early in the week Mr Andrews warned he would accept no amendments to the bill in the lower house. It remains to be seen whether assisted dying opponents will adopt similar delaying tactics in the upper house if it appears likely the bill will pass.

But what can be expected now is that they will fight a furious battle using any tools at their disposal to defeat the prospect that Victoria will become the first Australian state to introduce voluntary euthanasia.