Western Australia is set to become the second state to legalise voluntary euthanasia after proposed laws allowing terminally ill people to end their own lives passed the Upper House of Parliament.

Key points: The voluntary assisted dying bill passed the Legislative Council in a 24–11 vote

The voluntary assisted dying bill passed the Legislative Council in a 24–11 vote A total of 55 amendments to the original legislation have been passed

A total of 55 amendments to the original legislation have been passed It will now head back to the Lower House where a final vote will pass it into law

The controversial voluntary assisted dying bill is now destined to become law within days after being passed 24 votes to 11.

Legislative Council MPs voted in favour of the Government's legislation after weeks of prolonged debate, amid accusations of filibustering and bullying.

The bill will now return to the Legislative Assembly next week for a final vote on amendments introduced in the Upper House.

WA Parliament spent almost 102 hours considering the bill in great detail. ( ABC News: Manny Tesconi )

Premier Mark McGowan was unrepentant for the pressure he applied to the Opposition, and in particular Liberal MP and strident critic of the bill Nick Goiran, to push the bogged-down legislation along in the Upper House.

"Sometimes to make an omelette you have to break a few eggs," Mr McGowan said.

"I wanted to see this get to a vote, because if it just went on for endless debate, we'd never achieve it.

"And I think that was the aim of perhaps one member of the Upper House."

'It's democracy at work'

Legislative Council MPs spent almost 102 hours on speeches and the consideration-in-detail phase, where each of the 186 clauses was debated.

Mr Goiran spoke on every one of the clauses, prompting extended sitting hours that triggered the ire of Mr McGowan and Upper House Leader Sue Ellery.

Anti euthanasia protesters held rallies outside WA Parliament. ( ABC News: Hugh Sando )

Leader of the Opposition in the Upper House Peter Collier defended Mr Goiran during his final speech on the bill.

"It's not the death of democracy," Mr Collier told MPs in the chamber.

"It's democracy at work and I'm very proud of the role of Nick Goiran," he said, adding his Liberal colleague had been unnecessarily pilloried.

"It's an issue of life and death and this piece of legislation deserves ruthless scrutiny, which it received."

By the end, after MPs had sat until almost 1:00am on Wednesday night, even Mr Goiran had enough.

"I think everybody is happy if it's done," Mr Goiran said.

"But I've always said I'll never shirk the responsibility of serious scrutiny and lawmaking."

Nick Goiran led the Liberal debate of WA's voluntary euthanasia laws, speaking on each of the 186 clauses. ( ABC News )

Of the 55 amendments which were passed, 25 were Mr Goiran's.

The Government had insisted the legislation was sound and did not need amending when it came to the Upper House.

It has dismissed most of the changes as inconsequential and not impacting the operation or the integrity of the bill.

The Premier did not hide the fact the Government agreed to the amendments, including some of its own, for political expediency to ensure the passage of the bill.

Ms Ellery said about 400 amendments were also rejected.

"The amendments that we passed, we made a judgment on every single one of them as to whether they'd make the bill better, did they do any harm to the bill, and we applied that judgment to every single amendment that came before us," she said.

How will euthanasia work in WA?

Under the proposed laws, to be eligible a person would have to be terminally ill with a condition that is causing intolerable suffering and is likely to cause death within six months, or 12 months for a neurodegenerative condition.

To access the regime, a person would have to make two verbal requests and one written request.

Those requests would have to be signed off by two doctors who are independent of each other.

The choice of lethal medication would be a clinical decision from an approved list of drugs.

Self-administration would be the preferred method, but in a departure from the Victorian regime, a patient could choose for a medical practitioner to administer the drug.

In Victoria, a doctor can only administer the drug if a patient is physically incapable.

Voluntary euthanasia supporters also held rallies at Parliament House during the course of the political debate. ( ABC News: Hugh Sando )

Laws attacked as 'dangerous, reckless'

For Mr Goiran, it remained the "most dangerous piece of euthanasia legislation in Australian history."

He said unlike the Victorian legislation, there was no requirement for a specialist doctor to be involved and patients could self-administer the lethal medication with no supervision.

They also did not have to keep the medication in a locked box.

"It is reckless stuff," he said.

WA's euthanasia debate attracted famous supporters including TV personality Andrew Denton and former Australian cricketer Adam Gilchrist. ( ABC News: James Carmody )

Mr McGowan insisted the bill was sound and contained strong safeguards, which ultimately gave people the choice on how to end their lives and end suffering.

"I think it's an act of fundamental compassion," he said.

"It's the right thing to do and anyone whose had parents who have died in pain, I think they'll know what I'm talking about."

The legislation should easily clear its last hurdle, when MPs return to the Legislative Assembly on Tuesday for a special sitting to vote on the 55 amendments.

The bill sailed through the Lower House when it was initially introduced there, although it is understood one Labor MP planned to speak on every amendment, and Mr McGowan has warned there may not be a vote until Thursday.