A voluntary euthanasia bill has been voted down by one vote after a marathon late night sitting in the NSW upper house, but the "fight isn't over" yet.
The parliamentary vote came at the end of an emotional day on Thursday as MPs made pleas for and against the draft bill, which was eventually defeated by 20 votes to 19.
Nationals MP Trevor Khan introduced the private members' bill, which would have provided patients 25 years or older, whose deaths are imminent and are in severe pain, a choice to end their lives.
"(We'll) never give up the fight," an "exhausted" and "disappointed" Mr Khan told AAP on Friday.
"We will look at the bill to see if there are any improvements," Mr Khan said, noting he would watch what happens in Victoria where MPs are also in the middle of a marathon debate over the voluntary assisted dying laws.
Mr Khan said the Parliamentary Working Group on Assisted Dying would not be folding up.
"We've put so much effort in now, so many people who've relied upon it that we'll continue."
He said it was a time to "regroup" before re-introducing another draft bill before the next state election in March 2019.
"(We will) go back and see if there's anything different we could have done."
However, even if the proposed legislation had passed the upper house, it likely would have failed in the lower house where coalition Premier Gladys Berejiklian and Labor Opposition Leader Luke Foley have previously stated their opposition to any such legislation.