ADEALAIDE, Australia (AP) — An attempt to legalize voluntary euthanasia in an Australian state was defeated by a single vote in parliament on Thursday.

The South Australian Parliament rejected the bill on Thursday 24 votes to 23, after a heated overnight debate.

South Australia almost became the only Australian state or territory to allow assisted suicide.

Australia's Northern Territory became one of the world's first jurisdictions to legalize mercy killing in 1996. Renowned pro-euthanasia doctor Philip Nitschke helped four people die before the Australian Parliament overturned the law in 1997.

While the Australian Parliament can overturn territories' laws, it does not have the same power over state laws.

South Australia Premier Jay Weatherill said on Thursday he felt "gutted" by the defeat. But he was sure a new bill would be introduced in time.

The bill was introduced by an opposition lawmaker last month.

The major parties do not have policy positions on euthanasia, so lawmakers were given a rare opportunity to vote according to their consciences rather than along party lines. The original bill required patients to have a terminal illness and to be suffering unbearable pain that could not be relieved before they could access medical help to end their lives.

They also needed to have their decision endorsed by at least two doctors.

Several amendments were passed to tighten access to assisted suicide during the debate, including by making mental health assessments mandatory.

The Australian Christian Lobby, a lobby group, described the amended bill as a "cobbled-together compromise" and welcomed its defeat.

"As a just and compassionate society, we can find better ways to deal with the suffering which does not draw us into providing state-sanctioned killing," the lobby's managing director Lyle Shelton said.