Opponents of WA's voluntary assisted dying bill have failed in their attempt to put a final vote in State Parliament on hold until well into next year.

Key points: Voluntary assisted dying laws have already passed the WA Lower House

Voluntary assisted dying laws have already passed the WA Lower House A vote in the Upper House is expected to be tighter and last longer

A vote in the Upper House is expected to be tighter and last longer The laws would allow a person with a terminal illness to end their own life

The Upper House rejected crossbench MP Rick Mazza's attempt to hold another inquiry into the contentious bill, voting 29-6 against the proposal on Tuesday night.

Had the move been successful, it would have put debate on hold for months and prevented a final vote from being held until several months into the new year.

The motion from Mr Mazza, a member of the Shooters, Fishers and Farmers Party, was dismissed by some supporters of voluntary assisted dying (VAD) as a delaying tactic.

But Mr Mazza pointed to concerns about what he described as a lack of consultation with the Indigenous community and a feeling that debate was being rushed to claim it was necessary.

Rick Mazza launched the bid to delay the passing of the voluntary assisted dying bill. ( Facebook )

His motion called for the committee to look at whether the bill provided "for culturally appropriate end-of-life choices for Indigenous persons" and to examine end-of-life care in rural and remote communities.

"I think there needs to be a lot more work done in that area," he said.

Mr Mazza said he was concerned the bill, if passed, would result in deaths through coercion.

"The coercion will be unpoliced, unreported and unmanaged," he said.

A review by the Upper House's legislation committee is not uncommon for contentious bills, but the Government had urged MPs not to do that given there had already been reviews by a joint parliamentary committee and the ministerial expert panel.

The committee examines whether proposed legislation meets its intended aims.

The Government has been sufficiently concerned by the prospect of another inquiry that Premier Mark McGowan warned MPs against it during debate in the Lower House last month.

"Any additional inquiries would be a waste of time and taxpayer money," Mr McGowan said at the time.

"Moves to create another inquiry would be nothing more than a delaying tactic from the opponents of this bill, who never want to see it become law."

Liberal MP Nick Goiran, one of the highest-profile critics of the bill, strongly supported Mr Mazza's motion.

"It would say a lot about this chamber if we are prepared to send the animal welfare bill to the Legislation Committee for examination but we are not prepared to send the voluntary assisted dying bill," he said.

But the Government's Upper House leader, Sue Ellery, said another committee investigation would resolve nothing.

"There are no stakeholders who have not had the opportunity to put their views to us," she said.

Debate will now continue on the bill, with the Government aiming to hold a final vote by the end of the year.

Enough Upper House MPs have said they will support the legislation for it to pass, but the Government is concerned the bill could be heavily amended to the point of being unworkable.