A lawyer representing detainees at a U.S. naval base at Guantanamo Bay,Cuba, argued before the U.S. Supreme Court that his clients have the right to civilian hearings, similar to prisonersheld on American soil.

It's the third time the court has looked at Guantanamo Bay,whichto many serves as a global symbol of the United States's abuse of power.

"All have been confined at Guantanamo for almost six years, yet not one has ever had meaningful notice of the factual grounds of detention or a fair opportunity to dispute those grounds before a neutral decision-maker," said Seth Waxman.

Waxman also called the potentially historic case a fundamental test of the U.S. justice system.

Supreme Court justices asked Waxman what jurisdiction he believed the court had in the matter.

Waxman responded that becauseGuantanamo is a federal military prison, the U.S. justice system would have the same authority as if thefacility were situated on American soil.

Lawyers for the U.S. federal government, however, argued that these detainees were enemy combatants, and did not have the same rights and freedoms as normal American citizens.

The Bush administration also asserted that the Military Commissions Act, passed last year, strips Federal Courts of their ability to hear detainee cases.

Among the 350 detaineesremaining in Guantanamo Bay isOmar Khadr, who has been in U.S. custody since age 15 and is the only Canadian being held atthe prison.

Legal question centres on writ

Khadr, 21, was arraigned last month before a U.S. military judge,but his trial was delayed to give the defence more time to prepare. He's charged with throwing the grenade that killed a U.S. medic, Sgt. Christopher Speer, in a firefight in Afghanistan in 2002.

The process will likelydetermine whether detainees like Khadrwill not only be able to challengetheir detentions, but also the jurisdiction of the military tribunal attempting to try them, said the lead military lawyer for Khadr, Lt.-Cmdr.Bill Kuebler.

"What they're seeking very simply is the right to get back into a federal court," Kuebler told CBC News Wednesday in an interview from Washington.

The basic legal questionthe court is debating centres on a centuries-old writ called habeas corpus —the right to challenge one's imprisonment in a fair and impartial court of law.

TheU.S. administrationhas saidthe military commissions getting underway in Guantanamo Bay are more than adequate in providing a fair trial for those determined "unlawful enemy combatants."

But human rights groups argue that the Guantanamo military commissions are illegal because they do not offer the same protections as U.S. courts.

Vincent Warren, an activist with the Centre for Constitutional Rights, said outside the courtroom that "the procedures that have been put in place with respect to the men who have been in Guantanamo for six years are procedures that do not protect the very fundamental guarantees that make America, America."

He adds that he thinks that the Supreme Court will be convinced that "the rule of law is at stake here."

'They want to look their accusers in the face'

The White House has said it believes the Supreme Court and the entire federal court system have no role to play.

But others familiar with the militarycommissions say the detainees' requests are simple and more than reasonable.

"They want to look their accusers in the face,"said Charles Swift, a formerjudge advocate generalfor the U.S.military who once defended Osama bin Laden's driver before theSupreme Court.

"They want to be able to say, 'This is what I did.'They want to have an opportunity to exonerate themselves."

The U.S. administration created the commissions following the 2002 invasion of Afghanistan, arguing that neither military courts martial nor U.S. civilian courts were appropriate for trying the Guantanamo detainees because much of the evidence would involve sensitive issues of national security.

The Supreme Court has already ruled on Guantanamo Bay twice, both times dealing the administration of U.S. President George W. Bush a severe rebuke.

'Bizarre' process

In 2006, the court declared the established Guantanamo court system illegal, but the White House and Congress quickly established a new military tribunal system following the ruling.

Kuebler, however,labelled the top court's previous rulingsas merely "minor corrections" of the Bush administration's "bizarre" military commissions process, which he said was "designed to produce criminal convictions using evidence that could not form the basis for a prosecution in any regular court in the United States or the civilized world."

Hesaid it was unreasonablefor Canadians to expectthe court's ruling could lead to Khadr's release, as noU.S. court has ever ordered any of the detainees to be freed.

Despite other Western nations intervening on behalf of their citizens to free them from Guantanamo Bay, Prime Minister Stephen Harper and Peter MacKay, who was foreign affairs minister, have steadfastly expressed confidence in the U.S. government's ability to give Khadr a fair trial.

"If there is a fair outcome in Omar Khadr's case, it's going to be because the Canadian government does something, not because the U.S. courts do something,"Kuebler said.