The Canadian Bar Association is urging the federal government to expand its restrictive new law on assisted dying, allowing mature minors, people suffering strictly from psychological illnesses and those diagnosed with competence-eroding conditions like dementia to get medical help to end their suffering.

But even as the country's lawyers seek to extend the right to medical assistance in dying, the government is digging in its heels, maintaining that the facts on which the Supreme Court decided to strike down the ban on assisted dying are no longer applicable.

In a response to a court challenge of the new law, the government argues that the top court's findings of fact in the landmark Carter case last year 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 who are already close to a natural death — the government says those findings are no longer necessarily true.

"The defendant does not admit that these findings remain true today or that they are applicable in the present case," the government argues in a document filed in the Supreme Court of British Columbia.

Among the facts that the government suggests are no longer true are the top court's findings that:

Denying assistance in dying 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.

'Near death' requirement at issue

The government's argument is in response to a court challenge launched by the B.C. Civil Liberties Association and Julia Lamb, 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.

Lamb and the BCCLA contend the new law is unconstitutional and not compliant with the Carter decision because it would not allow an assisted death for people, like Lamb, who are suffering but not near death.

In a terse reply to the government's document, Joseph Arvay, lawyer for the plaintiffs, says the government "is estopped from disputing the factual findings made in Carter ... and to do so is an abuse of process."

Julia Lamb, who has a degenerative muscle disease, leaves a news conference in Vancouver, B.C., Monday, June, 27, 2016. Lamb is challenging Canada's physician-assisted dying law just days after it came into force. (Jonathan Hayward/Canadian Press)

Grace Pastine, the BCCLA's litigation director, said the government is essentially saying, "'We've crafted a brand new law and so now this is a brand new issue and you have to re-litigate and re-argue every issue related to physician-assisted dying all over again."'

The legal fight that culminated in the Carter ruling took four years and cost millions, she noted, adding that the government is creating "a real barrier to justice" by maintaining that battle must be fought all over again.

"If ordinary Canadians and public interest groups and pro-bono lawyers have to recreate the wheel every time they challenge an unconstitutional law, they're seriously disadvantaged against the bottomless pockets of the federal government," Pastine said in an interview.

But even as the government digs in, the CBA is urging it to adopt a more permissive approach to assisted dying.

At its annual meeting Thursday, the bar association's council unanimously passed three resolutions, urging the government to extend the right to assisted dying to people suffering strictly from psychiatric illnesses and to mature minors and to allow people diagnosed with conditions that will eventually cause loss of competence to make advance requests for an assisted death while they're still able to give informed consent.

The government has promised independent studies of those three issues, starting within six months and reporting back by the end of 2018.