Lawyers for Jose Padilla, a U.S. citizen held as an "enemy combatant" for nearly four years, want the Supreme Court to resolve how much power a president has while the nation is at war.

Lawyers Donna Newman and Andrew Patel told the high court in papers filed Tuesday that the justices must step in "to preserve the vital checks and balances" on the president.

In an another twist to the case, Solicitor General Paul Clement asked the Supreme Court Wednesday to order Padilla's transfer from military to civilian custody immediately.

In their filing, Newman and Patel cited the Bush administration's interpretation of the president's war powers to justify its decision to hold Padilla — until recently — without charges in a military brig in South Carolina.

Padilla's lawyers also said President Bush abused his war powers authority by approving warrantless surveillance of conversations between people in the United States and abroad who had suspected terrorist ties.

Such developments "underscore the need for this court to address the fundamental constitutional questions presented by this case," the lawyers wrote.

"The government continues to defend this sweeping view of the president's power to substitute military law for the rule of law and seeks to expand it further, arguing that the very authorities that it says justify the indefinite detention without charge of citizens also justify widespread spying on citizens without judicial warrant or Congressional notification," Padilla's lawyers said.

Padilla's appeal deals not only with the broad questions of presidential power, but also seeks to resolve whether Padilla should remain in military or civilian custody.

Last week, the Richmond-based 4th U.S. Court of Appeals urged the Supreme Court to take the case after chastising the administration for shifting its tactics in the Padilla case and warning the government that it was risking its credibility with the courts.

A three-judge appellate panel refused the administration's request to vacate a September ruling that gave Bush wide authority to detain "enemy combatants" indefinitely without charges on U.S. soil.

The decision, written by Judge J. Michael Luttig, questioned why the administration used one set of facts before the court for 3 1/2 years to justify holding Padilla without charges but used another set to convince a grand jury in Florida to indict him last month.

Clement, in Wednesday's emergency filing with Chief Justice John Roberts, said the appeals court overstepped its authority and its decision "defies both law and logic" because Padilla's lawyers also want him transferred to civilian custody.

He said the decision also was improper because it amounted to "an unwarranted attack on the exercise of executive discretion."

Roberts could rule himself or refer the transfer request to the entire high court.

Padilla, a former Chicago gang member, was arrested in 2002 at Chicago's O'Hare Airport as he returned to the United States from Afghanistan. Initially, then-Attorney General John Ashcroft alleged Padilla planned to set off a radiological device known as a "dirty bomb."

The administration then argued before federal courts in New York and Virginia that Padilla should be held without charges because he had come home to carry out an Al Qaeda backed plot to blow up apartment buildings in New York, Washington or Florida.

Last month, a grand jury in Miami charged Padilla with being part of a North American terror support cell that allegedly raised funds and recruited fighters to wage violent jihad outside the United States.