A ruling that allowed a prisoner to sue former Bush administration attorney John Yoo for devising the legal theories that justified his alleged torture threatens to "open the floodgates to politically motivated lawsuits" against government officials, Yoo's lawyers say.

In papers filed late Monday with the Ninth U.S. Circuit Court of Appeals in San Francisco, Yoo's new team of private lawyers argued that a judge's refusal to dismiss a suit by inmate Jose Padilla injected the courts into the political arena.

"Threatening executive branch lawyers with personal liability for reaching allegedly incorrect legal conclusions regarding the constitutionality of a president's wartime actions would infringe on the core war-making authority that the Constitution reserves to the political branches," said attorney Miguel Estrada.

Yoo, a UC Berkeley law professor, was a Justice Department lawyer from 2001 to 2003 and wrote a series of memos on interrogation, detention and presidential powers.

The best known was a 2002 document that said that rough treatment of captives amounted to torture only if it caused the same level of pain as "organ failure, impairment of bodily function or even death." The memo also said the president may have the power to authorize torture of enemy combatants.

Another Yoo memo said that U.S. military forces could use any means necessary to seize and hold terror suspects in the United States.

Padilla was arrested in Chicago in 2002 and accused of plotting with al Qaeda to detonate a radioactive "dirty bomb." He was held as an enemy combatant in a Navy brig for three years and eight months, then was taken out of the brig and charged with taking part in an unrelated conspiracy to provide money and supplies to Islamic extremist groups. He was convicted and sentenced to 17 years in prison.

Padilla's suit against Yoo covers his time in the brig. He says the government detained him illegally, denied him contact with the outside world for nearly two years, kept him for lengthy periods in darkness and blinding light, subjected him to temperature extremes, confined him in painful stress positions and threatened him with death.

Padilla says Yoo, a member of a Bush administration planning group known as the "war council," reviewed and approved his detention in the brig and provided the legal cover for his abusive treatment. His suit seeks a token $1 in damages, plus legal fees.

In his June 12 ruling, U.S. District Judge Jeffrey White in San Francisco said government lawyers, like any other officials, are "responsible for the foreseeable consequences of their conduct." He said Padilla had a right to sue the "alleged architect of the government policy" on enemy combatants.

The Justice Department, which had represented Yoo in the case, then withdrew and was replaced by private attorneys. They argued in Monday's appeal that Yoo, as a legal adviser to the president, had not been responsible for the decision to detain Padilla, for the conditions of his confinement, or for "any alleged violation of Padilla's rights."

In response, Padilla's lawyers said Yoo's arguments were the same ones White had already rejected. "Lawyers can't aid and abet their clients' crimes," they said in a statement. "And they can't aid and abet their clients' involvement in torture."

The appeals court has not set a hearing date in the case.

This article has been corrected since it appeared in print editions.