At issue, as the Supreme Court of Canada kicks off its fall session, is an appeal by Ontario in the case of an aboriginal man whose manslaughter conviction was thrown out because his jury had no First Nations members.
The decision was "so broad and powerful that it has potential to drastically change our approach to the jury system," the province argues in its factum.
In addition, according to the factum, the ruling has generated "considerable uncertainty" and holds the state to account for results "beyond its control."
The province argues the right of an accused to a fair and impartial jury does not entail an absolute right to a jury comprised in any particular way.
It's the first time Supreme Court will be dealing directly with the concept of a representative jury and what that entails.
The case arose in 2008 when a non-aboriginal jury in Kenora, Ont., convicted Clifford Kokopenace of stabbing a friend to death on the Grassy Narrows reserve. The Ontario Court of Appeal upheld the verdict in 2011.
However, in an unusual twist, the Appeal Court put its ruling on hold to deal with a constitutional challenge sparked by the years-long under-representation of aboriginals — a problem that only came to light at inquests into the deaths of two natives in northern Ontario in 2007.
The representation issue paralyzed jury proceedings — criminal, civil and inquest — in the region.
In response, the province asked former Supreme Court justice Frank Iacobucci to investigate and make recommendations. He reported last year that the system for recruiting aboriginal jurors was broken.
Soon after, in a landmark ruling on the constitutional challenge, the Court of Appeal ordered a new trial for Kokopenace. A majority of the justices found the province had violated his rights by failing to ensure aboriginals were properly represented on jury rolls.
"The integrity of the process was fundamentally compromised by the inattention paid by the state to a known and worsening problem, year after year,'' the court ruled.
In its appeal, Ontario calls on the Supreme Court to restore the conviction, saying Kokopenace had a fair trial despite the lack of aboriginals on his jury. It also says the province's top court went too far in trying to solve a real issue:
"Everyone who has been involved in this case has been struck by the low participation of aboriginal people in the jury process, and their simultaneous over-representation in the criminal justice system as accused and victims," the factum states.
"The Court of Appeal was understandably motivated to respond with whatever legal tools it had to remedy this serious problem. Unfortunately, the tool before it — the concept of jury representativeness — is ill-suited to the task."
For his part, Kokopenace's lawyers argue it was Ontario's "inaction" that allowed the problem to fester for more than a decade before his trial.
The Court of Appeal decision was "fully consistent with Canadian constitutional principles" and correct in finding the state had "failed to meet its representativeness obligations," they say.
"Jury roll representativeness is an essential safeguard of institutional impartiality in trials by jury, and indispensable to the jury's intended functions."
Intervening in the case are prisoner advocacy, aboriginal and legal groups.
ALSO ON HUFFPOST: