The Justice Department on Wednesday defied a federal judge for the second time, refusing to allow Zacarias Moussaoui (search) to question senior Al Qaeda (search) captives in preparation for his criminal trial.

Judicial punishment that could damage the prosecution is likely to follow.

U.S. District Judge Leonie Brinkema (search) has a range of options, including exclusion of government evidence, barring the death penalty and dismissing charges in the only case to arise from the attacks of Sept. 11, 2001.

Allowing the questioning "would needlessly jeopardize national security at a time of war with an enemy who has already murdered thousands of our citizens," the government said.

"Consequently, the government cannot, consistent with the interest of national security, comply with the court's order" of Aug. 29.

Prosecutors said they recognize the objection could lead to dismissal of the indictment, but asked Brinkema to postpone any action pending an appellate ruling.

Moussaoui is the only person charged as a conspirator in the Sept. 11 attacks.

The dispute between the Bush administration and the judge has delayed a trial for Moussaoui, but the Justice Department says the stakes are high for the nation. Prosecutors warned of grave consequences if Moussaoui is allowed to interrupt interrogations of Al Qaeda prisoners, who may be providing information on terrorism operations.

Brinkema concluded in rulings in January and last month that Moussaoui's constitutional right to potentially favorable witnesses does not outweigh those concerns. She ordered use of satellite communications to connect Moussaoui with the prisoners, held in undisclosed locations.

Once penalties are imposed, a panel of the 4th U.S. Circuit Court of Appeals (search) is expected to intervene in the dispute, which could lead to a precedent-setting ruling on the access of terrorism defendants to captives from the war on terrorism. The issue could go to the Supreme Court.

Moussaoui asked to question, among others, Khalid Shaikh Mohammed (search) — considered the mastermind of the Sept. 11 attacks — and Mustafa Ahmed Hawsawi (search), a suspected paymaster for Al Qaeda.

Brinkema granted the motion, as she did with an earlier request by Moussaoui to question an Al Qaeda planner of Sept. 11, Ramzi Binalshibh (search). The government also refused to make him available.

The Sixth Amendment to the Constitution normally grants defendants the right to compel the appearance of potentially favorable witnesses for pretrial questioning and to testify at trial. The government argued the amendment doesn't apply to wartime captives held outside the United States.

Brinkema had concluded that Moussaoui — who is representing himself — and a team of court-appointed lawyers assisting him, convinced the court the prisoners had made statements that would support Moussaoui's denial of involvement in the Sept. 11 conspiracy.

Moussaoui is charged with participating in a broad conspiracy that including planning for the Sept. 11 attacks, but also other aspects of a terrorism fight against the United States: religious edicts to kill U.S. soldiers in Somalia, training Al Qaeda terrorists for a holy war and attempts by Al Qaeda to obtain components of nuclear weapons.

Even if the Al Qaeda witnesses would not prevent a guilty verdict, they could influence the second phase of a trial, where jurors would determine whether Moussaoui received the death sentence the government is seeking.

A determination of Moussaoui's responsibility for the deaths on Sept. 11 could be the key factor in deciding whether he's eligible for capital punishment.