A court hearing begins today that will determine how long grievously ill Canadians must wait to find out if their right to a medically assisted death has been violated by the federal government’s restrictive approach to the issue.

The Supreme Court of British Columbia is scheduled to hear arguments over two days on the government’s contention that the facts on which the Supreme Court of Canada struck down the ban on assisted dying two years ago are not applicable to the new federal law.

The hearing is part of a constitutional challenge to the new law, which allows only those who are already near death to enlist medical help to end their lives.

If the government’s position prevails, it will mean the findings of fact made by the country’s top court during its landmark ruling, which is known as the Carter case, will be argued all over again.

It will mean “a later, longer and more costly trial,” said Jay Aubrey, counsel for the B.C. Civil Liberties Association, which is spearheading the constitutional challenge on behalf of Julia Lamb and Robyn Moro.

“In the meantime, people like Robyn Moro are left suffering intolerably, waiting for the right that was already given to them by our Supreme Court in 2015.”

The BCCLA is seeking a court order that the government be barred from relitigating issues that were already decided in Carter.

But the government argues that the top court’s findings of fact applied only in the context of the absolute ban on physician-assisted dying that existed at the time.

Now that there is a new law – which allows assisted dying only for incurably ill adults whose natural death is “reasonably foreseeable” – the government says those findings are no longer relevant.

“Canada will argue that those findings are not relevant to the issues in the present litigation and, in many instances, are no longer accurate,” government lawyers say in an affidavit filed last week with the B.C. Supreme Court.

The BCCLA’s argument that “this court should be bound by findings of fact made in a previous case involving different plaintiffs, a different legal regime and a different set of issues is entirely novel and without precedent,” the government contends.

Moreover, it says accepting the argument would be “highly prejudicial because it would preclude Canada from mounting a full defence of the new regime.”

The government contends that the Supreme Court ruling in 2015 was based solely on the medical condition of just one of the plaintiffs in that case – Gloria Taylor, who suffered from a terminal illness, amyotrophic lateral sclerosis.

It does not mention Kay Carter, after whom the case is named, who suffered from spinal stenosis, a painful but non-terminal condition.

Whereas Taylor had been given less than a year to live, the government says the plaintiffs in the current case, Lamb and Moro, suffer from different medical conditions that are at “different stages of progression.”

Lamb is a wheelchair-bound 25-year-old who suffers from spinal muscular atrophy, a degenerative disease that she fears will eventually consign her to years of intolerable suffering. She wants the “peace of mind” of knowing she can receive an assisted death when her suffering becomes unbearable.

Moro is a 68-year-old who suffers excruciating pain from Parkinson’s Disease but has been denied medical help to end her life because her natural death is not deemed to be reasonably foreseeable.

The two B.C. women, along with the BCCLA, are challenging the constitutionality of the new law on the grounds that it is more restrictive than the assisted dying regime envisioned by the Supreme Court in Carter.

The top court directed that medical assistance in dying should be available to consenting, competent adults with “grievous and irremediable” medical conditions that are causing enduring suffering that they find intolerable. It did not require that a person be near death.

Moro has said she’ll refuse food and water until she dies of dehydration if the constitutional challenge is rejected or takes years to resolve.

“She is living day-to-day at this point and cannot hold on much longer,” said Aubrey. “So we are in a race against the clock with Robyn.”

Among the Carter facts that the government suggests are no longer applicable are the top court’s findings that:

– Denying assisted death for people with grievous and irremediable medical conditions may condemn them to a life of severe and intolerable suffering.

– Such a person faces a “cruel choice”: take his or her own life prematurely or suffer until natural death.

– A permissive approach to assisted dying would not put Canada on a “slippery slope” in which disabled and other vulnerable Canadians are pressured to end their lives.

The government says expert evidence heard in Carter, particularly with respect to permissive assisted dying regimes in other countries “is no longer current” and that subsequent changes to those regimes will be important to consider “in assessing the efficacy of certain safeguards.”