The B.C. Civil Liberties Association is leading the charge for the group, including Gloria Taylor, who wants the court to strike down the law that bans such suicides as her health fades because of ALS, or Lou Gehrig's disease.
Grace Pastine, the association's litigation director, said Taylor simply wants the option of asking for such a death.
"That is not to say that Gloria is ready to die — she's not," Pastine said in an interview. "That will make her life now more comfortable and will give her great piece of mind."
Taylor became involved in the lawsuit last year when the symptoms of her amyotrophic lateral sclerosis became worse.
Pastine said Taylor's condition had deteriorated to the point where she's in a wheelchair and now needs a feeding tube.
"She's still spirited and lively, but her body is failing her."
The constitutional challenge involves the laws that make it illegal to help someone commit suicide.
At the start of the trial last year, the association asked B.C. Supreme Court Justice Lynn Smith to declare that the federal law preventing physician-assisted suicide infringes on the Canadian Charter of Rights.
If the court rules the government has some time to change the law, Pastine said the association asked the judge to rule that Taylor will still be able to ask for a doctor-assisted death.
During the trial, association lawyer Joe Arvay said evidence showed that people who want assisted suicide were already getting help illegally, just like back-alley abortions decades ago before those laws were changed.
The federal government's lawyer, Donnaree Nygard, told the court at the start of the trial in November that while the stories were heart wrenching, the potential harm of striking down the law was irreversible and would put the elderly, depressed and disabled at risk.
In September 1993, judges of the Supreme Court of Canada ruled 5-4 against an assisted suicide for Sue Rodriguez, who also had ALS.
But Pastine said much has changed since the Victoria, B.C., woman asked a doctor to help her die.
"Now there are a number of jurisdictions around the world that allow for physician-assisted dying, choice in dying."
She said they've learned from places like Oregon, the Netherlands and Belgium that it's possible to put in place a rigorous system of safeguards so that vulnerable people are protected and choice and dignity are also upheld.