The Federal Court has struck down several sections of the Citizenship Act relating to how the government may revoke someone's citizenship.
In a decision today, Justice Jocelyne Gagné said the provisions in question, which don't violate the Charter of Rights and Freedoms, do violate Canada's Bill of Rights "in a way that can not be avoided by interpretation."
She noted that citizenship revocation is an important decision that bars applicants from re-applying for 10 years while some could even be rendered stateless.
"Given the importance of Canadian citizenship and the severe consequences that could result from its loss, the principles of fundamental justice require a discretionary review of all the circumstances of the case," wrote Gagné.
Among those circumstances, she said, is a consideration of humanitarian and compassionate grounds.
Gagné then ruled three sections of the previous government's Strengthening Canadian Citizenship Act (SCCA) inoperative.
That means going forward, ministers of Citizenship and Immigration will no longer have the power to decide on their own to revoke someone's citizenship if they feel it was obtained by lying or concealing information.
It also overturns part of the law that allowed the government to revoke someone's citizenship without a hearing.
Immigration lawyer Lorne Waldman represented one of the eight people who challenged the law in court.
"We didn't understand why the current government would continue to use and support the current revocation process when all of the stakeholders were arguing it was an unfair process. But they did. So they forced us to go to court and now today the court decision is vindication of our position that this is not a fair process," Waldman told CBC News from Vancouver.
A spokesperson told CBC News that Citizenship and Immigration Minister Ahmed Hussen was not available to comment on today's ruling as he is travelling outside Canada.
"Our government will review the decision, and until that review is completed commenting as to next steps will need to await the review," said Bernie Derible.
In her ruling, Gagné highlighted the case of Thomas Gucake, "for whom in my view, humanitarian and compassionate grounds should have been considered."
Gucake moved to Canada from Fiji with his parents when he was a child and was granted citizenship in 2005 when he was 18 years old.
Two years later, he joined the Canadian Armed Forces and went on to serve with the Second Battalion Princess Patricia's Canadian Light Infantry for seven years, and did three tours to Afghanistan. After winning several certificates and awards for his deployments, he was honourably discharged in 2014.
In November 2015, Gucake received a notice that the government was moving to revoke his citizenship.
"The report to the minister contained information received in 2007, eight years prior to the coming into force of the SCCA, alleging Mr. Gucake's father may have failed to disclose a minor criminal conviction in Australia," wrote Gagné.
"It seems highly unfair to me that under the amended act, there is no requirement that Mr. Gucake's personal situation be considered by the immigration officer," she said.
In her ruling, Gagné also declared all eight of the notices or decisions to revoke citizenship null and void.
As for subsections 10 (1), (3) and (4) while the judge declared them inoperative because they violate the Bill of Rights, she did not find they violated the Charter of Rights and Freedoms. As such, the judge suspended her judgment for 60 days to give the government time to decide if it wants to file an appeal.
Those provisions drew a great deal of attention last fall when the Status of Women Minister Maryam Monsef was informed that she had been born in Iran, not Afghanistan as she had been told by her mother. Such grounds would conceivably have been enough for Monsef to lose her Canadian citizenship under the current law.