Canada's highest court has unanimously struck down a ban on doctor-assisted suicide for mentally competent but suffering and "irremediable" patients.
The Supreme Court's decision sweeps away the existing law and gives parliament a year to draft new legislation that recognises the right of consenting adults who are enduring intolerable suffering to seek medical help to end their lives.
The judgment said the current ban infringes on the life, liberty and security of individuals under Canada's constitution. It had been illegal in Canada to counsel, aid or abet suicide, an offence carrying a maximum prison sentence of 14 years.
The decision reverses a ruling the Supreme Court made in 1993. At the time, the court was primarily concerned that vulnerable people could not be properly protected under physician-assisted suicide.
The court ruling said: "An individual's response to a grievous and irremediable medical condition is a matter critical to their dignity and autonomy."
The judgment added: "The law allows people in this situation to request palliative sedation, refuse artificial nutrition and hydration, or request the removal of life-sustaining medical equipment, but denies the right to request a physician's assistance in dying."
Assisted suicide is legal in Switzerland, Germany, Albania, Colombia, Japan and in the US states of Washington, Oregon, Vermont, New Mexico and Montana. Euthanasia is legal in the Netherlands, Belgium and Luxembourg.
Grace Pastine, litigation director for the British Columbia Civil Liberties Association, welcomed the ruling, saying: "For seriously and incurably ill Canadians, the brave people who worked side by side with us for so many years on this case - this decision will mean everything to them."
The pressure will now be on parliament to act in an election year, as the court said no exemptions can be granted for those seeking to end their lives during the 12-month suspension of the judgment.
The case was spurred by the families of two now-dead British Columbia women, supported by Ms Pastine's organisation.
Gloria Taylor was diagnosed with Lou Gehrig's disease, a degenerative neurological illness, and Kay Carter was diagnosed with a degenerative spinal cord condition. At the age of 89, Ms Carter travelled to Switzerland, where assisted suicide is allowed.
Ms Taylor had won a constitutional exemption at a lower court for a medically assisted death in 2012, but that decision was overturned in subsequent appeals. She died of an infection later the same year.
It has been more than 20 years since the case of another patient with Lou Gehrig's disease, Sue Rodriguez, gripped Canada as she fought for the right to assisted suicide. She lost her appeal but took her own life in 1994, at the age of 44, with the help of an anonymous doctor.