A group suing Dick Cheney to preserve a wide range of records from his time as vice president can depose one of his top aides, federal courts ruled Friday.

U.S. District Judge Colleen Kollar-Kotelly ordered Claire O'Donnell, the vice president's deputy chief of staff, to make herself available to lawyers from a private group, Citizens for Responsibility and Ethics in Washington, known as CREW.

CREW is suing Cheney and the Executive Office of the President in an effort to ensure that no presidential records are destroyed or handled in a way that makes them unavailable to the public.

The group had wanted to depose Cheney's chief of staff, David Addington, but a three-judge panel at the U.S. Court of Appeals for the District of Columbia said deposing Addington "would constitute an 'unwarranted impairment' of the functioning of" the vice president's office.

Appellate judges Douglas H. Ginsburg, David S. Tatel and Thomas B. Griffith ordered that another aide be substituted, but they refused to throw out Kollar-Kotelly's order requiring the deposition.

Cheney's lawyers contended the depositions were an unprecedented intrusion into the vice president's prerogatives, but the appellate judges said the deposition would "cause little to no inconvenience."

The lawsuit claims the Bush administration's actions raise questions over whether the White House will turn over records created by Cheney and his staff to the National Archives in January. In 2003, Cheney asserted that the vice president's office is not an entity within the executive branch.

Addington told Congress this summer that the vice president belongs to neither the executive nor legislative branch of government, but rather is attached by the Constitution to Congress. The vice president presides over the Senate.

"Today's decision, allowing CREW discovery in our case against the Office of the Vice President, moves us one step closer to ensuring that important historical documents will not be lost to future generations," said Anne Weismann, CREW's lawyer.