The case centres on Joseph Ryan Lloyd, an addict from Vancouver's Downtown Eastside who was convicted of drug trafficking after police caught him with less than 10 grams combined of heroin, crack cocaine and crystal methamphetamine.
Under new federal legislation brought in in 2012, that conviction carries an automatic one-year sentence, but the provincial court judge in the case balked at the lack of discretion that left him and declined to impose the sentence.
"It is a sentence which Canadians would find abhorrent or intolerable," Judge Joseph Galati said in his written ruling last year.
"Accordingly, I find that the mandatory minimum sentence of imprisonment for one year … constitutes cruel and unusual punishment."
The B.C. Court of Appeal sided with the Crown, against Galati's ruling, but the case was appealed to the Supreme Court of Canada.
"We are thrilled with the Supreme Court's decision to hear Mr. Lloyd's appeal," said Adrienne Smith of Pivot Legal Society, which has been an intervenor in the case at earlier stages, in a press release.
"Mandatory minimum sentences unfairly target vulnerable Canadians and fail to consider the conditions of individual's lives and their communities."