Although the two main figures in the case have died, the B.C. Civil Liberties Association's effort to change the law continues.
The ruling takes another look at the issue, the first since the 1993 decision in the Sue Rodriguez case, which upheld the law against assisted suicide in a 5-4 decision.
Kay Carter and Gloria Taylor were the key plaintiffs and they won at the British Columbia Supreme Court, which ruled that the assisted suicide law violates the rights of the gravely ill.
Carter, 89, travelled to Switzerland in 2010 to end her life and Taylor died in 2012, before the provincial court of appeal overturned the initial court ruling.
The case was appealed to the Supreme Court of Canada, which agreed to revisit the issue.
The civil liberties group says it believes that people who are suffering unbearably at the end of life should have the right to choose a dignified and peaceful death.
"Canadians who suffer from diseases such as terminal cancer, Huntington’s disease and multiple sclerosis should be able to choose a compassionate death," the association says on its website.
"They also deserve the peace of mind and improved quality of life that comes with knowing that should their suffering become intolerable, a peaceful and dignified physician-assisted death will be an available choice."
The case attracted submissions from 20 interveners, including provincial attorneys-general and religious groups.
The federal government also intervened, urging the court to uphold the Rodriguez decision.
It said the arguments have not changed significantly since that ruling.
"What also has not changed since 1993 are the two objectives that underscore the need for an absolute prohibition against assisted suicide," the government said in its factum.
"The preservation of life and the protection of vulnerable people — the poor, the elderly, people with disabilities — are societal interests of the highest order."
The Catholic Health Alliance of Canada, for example, argued against the right to assisted suicide.
"The alliance submits that the proper medical means with which to provide dignity to patients in the final stages of their lives, including the stages in which patients may be in pain, is by providing comfort through spiritual and palliative care," it said in its submission to the court.
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