A dozen legal scholars, including a noted civil libertarian, Alan Dershowitz, are coming to the aid of a convicted White House aide facing a 2 1/2-year prison sentence. The scholars submitted an amicus brief Thursday to Judge Reggie Walton arguing that that there are serious constitutional questions about the legal authority of the special prosecutor who pursued Libby on obstruction of justice, perjury and false statement charges, Patrick Fitzgerald.

"With no supervisor, Special Counsel Fitzgerald is too independent to make his supposed 'superiors' politically accountable for his actions and it is at the very least a close question whether the mere power of removal does anything to solve the problem," the scholars argued.

The issue is one of those which the defense contends could lead to Libby convictions being overturned on appeal. Judge Walton has already concluded that Libby's appointment was constitutional. However, if the defense or the law professors convince the judge that there is a "substantial" possibility that higher courts might disagree, Libby could be released on bail.

Bail remains a critical question for Libby. Judge Walton has indicated he is not inclined to grant it. Many political observers believe that if Libby gets bail and his appeals fail, he stands a better chance of receiving a presidential pardon because President Bush's term will be nearing its end.

Technically, the scholars took no position on the question of bail, but if Judge Walton agreed with them, bail would be highly likely.

Mr. Dershowitz's presence on the brief is perhaps most notable because the Harvard professor has been viewed in many quarters as political liberal, at least until recently. Many of the other scholars who joined in are known libertarians or conservatives, such as a failed Supreme Court nominee of President Reagan, Robert Bork, who taught at Yale.

The remaining professors joining the brief were Vikram Amar of the University of California Hastings, Randy Barnett and Viet Dinh of Georgetown, Douglas Kmiec and Robert Pushaw of Pepperdine, Richard Parker of Harvard, Gary Lawson of Boston University, Thomas Merrill of Columbia, Earl Maltz of Rutgers, Robert Nagel of the University of Colorado.

The legal question centers on whether a 1988 Supreme Court decision, Morrison v. Olson, which upheld the constitutionality of a now-expired independent counsel statute, renders Libby's appointment lawful. Libby was appointed to resolve potential political conflicts of interest in the Justice Department. He was subject to removal by the acting Attorney General, but was not under the department's day-to-day supervision.