A three-judge panel of the U.S. Court of Appeals declined to order White House Chief of Staff Josh Bolten and former White House Counsel Harriet Miers to testify before a House committee investigating the dismissals, The Washington Post reported. The panel said the investigation into claims that federal prosecutors were fired in 2006 for partisan political motives would not be "fully and finally resolved" while the 110th Congress is still in session.

Bolten and Miers are appealing a lower court ruling in July that they are required to testify and produce documents under the subpoena. The appeal claims the subpoena violates President George W. Bush's executive privilege.

"The present dispute is of potentially great significance for the balance of power between the legislative and executive branches," the judges said in Monday's opinion.

U.S. Attorney General Michael Mukasey last week appointed a special prosecutor to decide whether criminal charges should be brought against his predecessor, Alberto Gonzales, and others for their roles in dismissing the U.S. attorneys.

The appointment came after the release of a report by the Justice Department inspector general that concluded the firings were carried out "at a minimum" in a "haphazard, arbitrary and unprofessional" manner.