Opponents of a voluntary assisted dying (VAD) bill in Western Australia face fresh accusations of filibustering after a Liberal MP moved hundreds of amendments to the proposed legislation.

Key points: The amendments by Nick Goiran increase doubts a final vote will be held this year

The amendments by Nick Goiran increase doubts a final vote will be held this year Debate on the issue had already slowed to glacial pace before the latest development

Debate on the issue had already slowed to glacial pace before the latest development Mr Goiran has rejected suggestions he would seek to filibuster the debate

Liberal MP Nick Goiran — a high-profile opponent of voluntary euthanasia — gave notice of 357 proposed amendments to the Government's bill during debate on Wednesday night, adding to the growing doubt about whether a final vote will be held this year.

Dozens of those amendments seek to replace references to "assisted dying" in the bill with "euthanasia and assisted suicide", but there are also scores of other proposed changes.

Mr Goiran's amendments would mandate a psychiatric assessment before a patient could be approved for VAD under the proposed scheme — a proposal that supporters of the Government's bill argue would make it unworkable.

There have been several rallies outside Parliament both for and against VAD laws. ( ABC News: Hugh Sando )

The 64-page list of amendments also includes changes proposed by other MPs, including Labor's Martin Pritchard, One Nation's Colin Tincknell and independent Charles Smith.

Supporters of the Government's bill dismissed the lengthy list of amendments as an obvious attempt to delay a final vote.

"Three hundred and fifty seven amendments from the lead speaker for the Liberal Party is extraordinary," Labor's Upper House leader Sue Ellery said.

"I can only assume [Liberal leader Liza] Harvey has endorsed him doing that on behalf of her party."

The first of those proposed amendments was defeated 28 votes to five, with no other Liberal MPs supporting it.

MP is trying to wreck the bill: Premier

Premier Mark McGowan said Mr Goiran's behaviour in Parliament was disgraceful.

"It's worse than filibustering, it's just trying to wreck the bill," he said.

"This is a guy who because he doesn't think he can win the vote, he's now just going to delay it so much that it can never get to a vote.

"It's unacceptable to me. I think it's unacceptable to the vast majority of Western Australians."

Premier Mark McGowan has called on Opposition Leader Liza Harvey to "pull Mr Goiran in line." ( ABC News: Gian De Poloni )

Mr Goiran rejected suggestions that he was attempting to filibuster the debate.

"Nothing could be further from the truth," he said.

"The simple amendments that are being put forward is to lift the standard of the Western Australian legislation to that of Victoria and Northern Territory. At the moment it's the most dangerous in the nation.

"Clearly the Premier has not read the amendments on the notice paper because had he done so he would understand that a significant number of them are simply the amendments that were proposed in the Lower House."

While many of Mr Goiran's proposed amendments were "consequential" or overlapping, meaning they would not need to be voted on individually, they included scores of significant changes.

Time running out for Christmas outcome

The debate had already slowed to a glacial pace before Mr Goiran put forward his long list of amendments.

Days of debate had failed to progress beyond the bill's second clause. There are 184 in total.

With just three sitting weeks left before State Parliament rises for its summer recess, the slow progress has cast significant doubt over whether there will be a final outcome before Christmas.

The Upper House voted 25 to 10 in support of the bill last week, but a final vote will only be reached after every one of the 184 clauses has been considered.

The Government is also preparing to make several changes of its own to the bill — despite fighting strongly against amendments during proceedings so far.

The Government has given notice of seven proposed amendments that would be voted on during a later stage of debate.

While most of those make minor wording changes, one would remove a rule stipulating that family members cannot witness a patient's request to access assisted dying.

Another would require a doctor to outline the palliative care options available to a patient in the official report they provide.

Those amendments have been moved following negotiations with the Australian Medical Association and other MPs.