Abortion would be decriminalised in NSW under a proposal to be put forward by the Greens and welcomed by health groups and advocates, who say NSW has some of the most restrictive laws in Australia.

Greens MLC Mehreen Faruqi will take the first step on Thursday to introducing a bill that would remove abortion from the Crimes Act entirely, by giving formal notice of her intention to the Parliament.

Ms Faruqi said she wanted to work with Liberal and Labor parliamentarians on the bill, which she said was the first to decriminalise abortion in NSW. However, one Labor MP has warned it could have unintended consequences if opponents amend it to further restrict abortion access.

Abortion now is a crime, although court decisions have established that it will not be found unlawful if a doctor believes it is necessary to save the woman from serious danger to her life, or mental or physical health. It is believed to be one of the more commonly performed medical procedures in Australia, at about 70,000 annually.

Ms Faruqi said getting the law through would not be easy, ''especially as many people are not even aware of the shaky status of the current law''.