The U.S. Supreme Court has heard a plea that terrorism suspects being held at the U.S. Naval base at Guantanamo Bay, Cuba, should be given the opportunity to challenge their detention in American courts. VOA National Correspondent Jim Malone reports from Washington.

Demonstrators outside the court chanted and waved signs calling on the nine high court justices to grant the detainees habeus corpus, the age-old legal principle that allows prisoners to challenge their detention before a neutral judge.

Inside the court, attorney Seth Waxman argued on behalf of a group of 37 detainees, part of the 305 prisoners now being held at Guantanamo.

"All have been confined at Guantanamo for almost six years," he said. "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."

But Waxman appeared to have little success in convincing some of the high court's more conservative justices that the Guantanamo detainees have a constitutional right to challenge their detentions in court.

Among the skeptical was Supreme Court Justice Antonin Scalia.

"You are appealing to a common law right that somehow found its way into our Constitution without, as far as I can discern, a single case in which the writ [right] was ever issued to a non-citizen," he said.

Some of the other justices appeared more sympathetic, including Justice Stephen Breyer.

"Now it has been six years, and habeus is supposed to be speedy, and yet people have serious arguments anyway that they are being held for six years without even having those arguments heard," he said.

The Supreme Court ruled against the Bush administration in two previous cases concerning the legal rights of the Guantanamo detainees.

Congress got involved in the issue in 2006 and passed a law that was designed to keep detainee appeals out of the civilian court system and refer them instead to military commissions.

But civil and legal rights groups say the alternative procedures set up by Congress and the Bush administration deprive the detainees of basic rights.

"At issue here that the Supreme Court decided was; 'Do we have a king in this country who is not bound by the rule of law and not bound by the Constitution? Or do we have a president that is subject to the Constitution?," said Vincent Warren, executive director of the Center for Constitutional Rights.

Conservative legal scholars argue against U.S. constitutional protections for foreign terrorist suspects.

"If the courts are going to be in charge of the conduct of warfare, we are going to be a much less safe country," said Andrew McCarthy, who is with the Foundation for Defense of Democracies.

A decision by the Supreme Court in the Guantanamo case is expected before the end of June.