A federal judge yesterday openly questioned the government's ability to prosecute Zacarias Moussaoui at a public trial, chastising the "shroud of secrecy" under which U.S. intelligence officials have classified a raft of pleadings and briefs in the case.

U.S. District Judge Leonie M. Brinkema's sharply worded two-page order came one day after a group of newspapers and broadcasters challenged the sealing of filings, which accelerated after the October capture in Pakistan of Ramzi Binalshibh, alleged planner of the Sept. 11, 2001, terror attacks.

Prosecutors have argued that certain documents must be sealed because of national security concerns.

"The court, too, is disturbed by the extent to which the United States' intelligence officials have classified [materials] . . . and further agrees with the defendant's skepticism of the government's ability to prosecute this case in open court," Brinkema wrote in response to Moussaoui's otherwise routine request for a hearing transcript and a memorandum opinion.

Moussaoui, who is representing himself, is charged with conspiring with al Qaeda operatives to hijack the airplanes that crashed into the World Trade Center and Pentagon. He and the lawyers appointed by the court to help him believe that Binalshibh may have information that will help their case. The intelligence community has continued to object to a defense interview, contending that it would disrupt its interrogation of Binalshibh at a critical point in the campaign against al Qaeda.

The U.S. Court of Appeals for the 4th Circuit is reviewing a Jan. 30 decision by Brinkema, also made in secret, that granted Moussaoui's attorneys access to Binalshibh, the self-described planner of the Sept. 11 attacks.

The government is invoking unprecedented national security powers in asking the appellate court to deny Moussaoui access to Binalshibh and is arguing that civilian courts should not interfere with military decisions, according to sources with knowledge of secret court documents. If the government does not win its appeal, it will probably not prosecute Moussaoui in a civilian court

Barbara Comstock, a Justice Department spokeswoman, said prosecutors are well within the law. "We regularly hold terrorists and spies accountable in court, while safeguarding both national security and due process," she said in a statement. "Congress has expressly provided a way to handle these cases . . . We are confident in the ability of our system of justice to try these cases under the procedures adopted by Congress and regularly upheld by the courts."

The case has become a fierce battle over the government's right to protect national security and a defendant's constitutional right to information and witnesses who could help his case. Brinkema's order only increases that tension, legal experts said.

"The judge is pointing out that it is the government's choice: You can't prosecute someone on a capital charge and withhold from him key evidence for his defense," said Kate Martin, director of the Center for National Security Studies, a civil liberties organization based in Washington. "It's unfair and prohibited by the due process clause."

Moussaoui, 34, a French citizen, is the only person charged in the United States in connection with the Sept. 11 attacks. He could face the death penalty if convicted. He had requested unclassified, uncensored copies of the transcript of a closed Jan. 30 hearing and a secret opinion the court issued last March 10. In yesterday's order, Brinkema told the government to respond.