The life expectancy of those allowed to seek voluntary euthanasia is a key issue, with the current 12 months likely to be reduced to six months.

With debate on the right-to-die laws to resume in the Parliament's 40-member upper house on Thursday, at least two MPs maintained they would not support the bill in its present form.

Liberal Simon Ramsay has joined independent James Purcell in saying he wanted amendments to the legislation.

The Andrews government is privately resigned to its bill being amended in order to get it passed, with Labor figures conceding voluntary euthanasia will probably end up being available only to people in the last six months of their lives.

The legislation originally allowed terminally ill Victorians with up to 12 months left to live to be eligible for an assisted death.

As MPs prepared for the renewed parliamentary debate, advocacy group Go Gentle published opinion polling of 2200 voters in western Victoria, including the electorates represented by Mr Ramsay and Mr Purcell.

The group's polling found 84 per cent of those surveyed supported the idea of a doctor being allowed to provide a lethal dose of medication to a terminally ill patient.

Mr Purcell said earlier this week he would demand that any person seeking an assisted death would be medically assessed as having six months to live rather than 12 months.

He also wants the patient's GP to play a role in the process.

Mr Ramsay, said he supported an assisted dying regime but held strong concerns that he wanted addressed.

Mr Ramsay confirmed he was finalising his set of amendments to the bill.

He wants the life expectancy for someone wishing to end their lives to be reduced to three months.

And Mr Ramsay said funding for palliative care should be increased so people in regional Victoria had equal access to support at the end of their lives.

He also cited concerns about the Voluntary Assisted Dying Review Board, saying appointments to the board should not be made by the health minister of the day.

"I'd get some more comfort if the panel was totally independent and at arm's length from the minister's choice."

But Professor Brian Owler, who chaired the ministerial advisory panel on voluntary assisted dying, said extensive consultation had gone into the current bill.

"It's difficult to ignore the sum of all those hundreds of people who have been consulted through this process," he said.

Upper house President Bruce Atkinson said on Wednesday he would not have a final position until he had seen amendments.

Nationals MP Melina Bath said after months of deliberation she had decided against supporting the bill.

"I have too many concerns in relation to the supposed safeguards but will reserve my right to assess any amendments as they come forward in debate," she said.