The bill, which the Sydney MP has been drafting for the past six months, will be released to the public next week, before it is introduced in parliament in August.

Advocates hope it could be law by Christmas.

A lot has changed since voluntary assisted dying failed to pass the Legislative Council by one vote in 2017.

"Four years ago, no other state had progressed with voluntary assisted dying, now every other state has," Mr Greenwich told AAP.

That drastically boosts the chances of success this time, he says, as NSW has "tried and tested" laws interstate to model theirs off.

"(They have) been able to show that a lot of the concerns of opponents are actually not borne out in reality," he said.

Protections for entities - such as aged care homes or hospitals - that do not wish to facilitate voluntary assisted dying will also be enshrined in the bill.

"We know that is a concern, particularly among faith-based organisations, (and) is a concern of MPs," Mr Greenwich said.

"Having these provisions in the bill is a sign of good faith that I want to work with stakeholders in the community and in the parliament, regardless of their view on voluntary assisted dying, to make sure we have appropriate legislation with robust safeguards."

"This will be a very conservative voluntary assisted dying piece of legislation."

Mr Greenwich is aiming for the bill to have more co-sponsors than any other in Australian history, as a reflection of the widespread community support for the law reform.

But Mr Greenwich says he need support from members of all parties for the bill to pass.

In a statement, NSW Labor leader Chris Minns said he did not support the law reform, but all Labor MPs would be encouraged to vote their conscience on the bill.

Mr Greenwich says there has been strong support for the bill from the crossbench and from members of the National Party, however Premier Gladys Berejiklian has previously said she does not want parliament to debate the topic.

She has also previously said she is personally uncomfortable with such a policy.

Treasurer Dominic Perrottet has said cabinet will decide whether to support the bill or permit a conscience vote for coalition MPs when it sees the legislation.

"I do hope that members of the Liberal Party will have the same right of every other member of the parliament to express a conscience on this issue," Mr Greenwich said.

Dying with Dignity NSW spokeswoman Shayne Higson says it's about time NSW caught up with other states.

"They have fallen behind," she told AAP.

"This is an issue that has had a widespread community support for many, many years - for decades."

Ms Higson cites polling from 2019 that showed the majority of people in every electorate in Australia want the law reform.

She is "quietly confident" the legislation will pass parliament this year.

"I'm confident that it will strike the right balance between respecting individuals rights not to participate in this law, but also ensuring that patients are able to access a legal option of end of life when their suffering becomes unbearable."

"And I'm confident that a majority of MPs will listen to their constituents, and use common sense."

Australian Associated Press