The Bush administration is back at the Supreme Court to defend its indefinite detentions of foreign terrorism suspects at the U.S. naval base at Guantanamo Bay, Cuba. Some men have been held there nearly six years.

At issue is whether the right to contest detention in U.S. civilian courts, enshrined in the Constitution, extends to the 305 men being held at Guantanamo as "enemy combatants."

The court is hearing arguments Wednesday in a highly anticipated case. It is the third time since 2004 that the Supreme Court has examined the administration's detention program.

The justices have ruled against the administration in the two earlier cases.

Lawyers for the foreign detainees argue that the courts must step in to rein in the White House and Congress, which changed the law to keep the detainee cases out of U.S. courts following earlier Supreme Court rulings. The most recent legislation, last year's Military Commissions Act, strips federal courts of their ability to hear detainee cases.

Seth Waxman, the top Supreme Court lawyer in the Clinton administration, is representing the detainees. "After six years of imprisonment without meaningful review, it is time for a court to decide the legality of" their confinement, Waxman said.

Solicitor General Paul Clement, representing the administration, said foreigners captured and held outside the United States "have no constitutional rights to petition our courts for a writ of habeas corpus," a judicial determination of the legality of detention.

The case could turn on whether the court decides that Guantanamo is essentially U.S. soil, which would make the case for detainee rights stronger. Justice Anthony Kennedy, widely thought to be a pivotal vote in this case, said as much in a concurring opinion in Rasul v. Bush, the 2004 case that was the court's first foray into the administration's detention policies.

"Guantanamo Bay is in every practical respect a United States territory," Kennedy said.

The administration also argues that panels of military officers that review the detainees' status as enemy combatants are adequate, even if the Supreme Court decides they have the right to contest their confinement.

The justices, however, decided to review the issue in June, after having turned down the detainees' appeal in April. They provided no explanation, but their action followed a declaration from a military officer who criticized Combatant Status Review Tribunals.

The United States has no plans to put most of those held at Guantanamo on trial. Just three detainees face charges under the Military Commissions Act and the military has said it could prosecute as many as 80.

The consolidated cases are Boumediene v. Bush, 06-1195, and Al Odah v. U.S., 06-1196.