One-time enemy combatant Jose Padilla suffered a legal setback at the U.S. Supreme Court Monday. But the high court refused to take a position on the central question in the case, whether President Bush has the power to order Americans captured in the war on terror held indefinitely without trial.

Jose Padilla, center, is escorted to waiting police vechicle by federal marshals

By a vote of six to three, the Supreme Court decided not to hear an appeal from Jose Padilla challenging the three years he was held as an enemy combatant in the war on terror.

Padilla is a former Chicago gang member arrested in 2002 in connection with an alleged radiological bomb plot.

He was held as an enemy combatant without charge for three years until he was transferred from military to civilian custody last year and charged with being part of a North American terror cell.

Monday's Supreme Court ruling rejected Padilla's appeal to consider whether President Bush has the power to indefinitely detain American citizens suspected of terrorism.

In effect, six of the nine Supreme Court justices sidestepped the case on technical grounds, disappointing Padilla's lawyer, Donna Newman.

"It is time for Congress to act and make the parameters and limitations that we have asked for because we think it is very important for the American people," she said.

Legal observers say the court will have to tackle the central question in the case another day.

Eric Holder was a deputy attorney general in the Clinton administration.

"This is one of those consequential decisions or potentially consequential decisions that really go to the heart of presidential power," he said, "and it is the kind of precedent setting decision that I think the Supreme Court should render an opinion on and I think it is very unfortunate that the court has decided not to take this case."

The Bush administration argued that the appeal was moot because Padilla is no longer being held as an enemy combatant.

The administration has said it had the power to detain Padilla since his arrest in 2002 as part of its overall legal strategy in fighting the war on terror.

"We are dealing with a new kind of threat, a new kind of enemy and that has required new thinking and new strategies by the administration," Attorney General Alberto Gonzales said.

Padilla has pleaded innocent to the new terror charges in Florida and will go on trial later this year. The previous charges about his alleged involvement in a so called dirty bomb plot are not included in the current set of criminal charges.