Alexandria, Va. ? The Bush administration asked a judge Friday to stop all proceedings against Zacarias Moussaoui, the lone individual charged in the Sept. 11 attacks, until an appeals court settles national security questions.

A government official, who would not be identified by name, indicated a crucial question was whether Moussaoui should have the right to question, or receive statements, from Ramzi Binalshibh — a suspected al-Qaida mastermind who is in custody.

The indictment says Binalshibh has been in contact with Moussaoui. The government might consider his statements so sensitive that it would move the Moussaoui case to a secret military tribunal rather than permit Binalshibh to reveal information at a public trial.

“Under the current circumstances of this case, it would be impracticable to continue this litigation until the issues presented to the 4th Circuit are resolved,” said the motion by U.S. Atty. Paul McNulty in Alexandria, referring to the 4th U.S. Circuit Court of Appeals in Richmond.

Jury selection is set to begin May 27, and the trial is scheduled for June 30.

U.S. District Judge Leonie Brinkema, who is hearing the Moussaoui case, issued a secret order in the Binalshibh matter last week. Moussaoui, representing himself, reportedly wants to question Binalshibh, and a defendant normally has the right to question witnesses who potentially could help the defense.

The implications of the appeal could range far beyond the Moussaoui case. If Binalshibh’s testimony is admitted, this could set a precedent that could bring statements from other captured individuals into court in public trials.

Atty. Gen. John Ashcroft has said he prefers to keep the case in the criminal justice system.

Brinkema, who did not immediately rule on the request to halt the proceedings, allowed the motion to be filed publicly because it did not reveal the issues involved. For several months, she has handled virtually all matters in the case in closed session.

If the government can’t keep Binalshibh’s statements from the public, “I think this trial will be stopped dead in its tracks, and the Bush administration will move to put it before a military tribunal,” said Robert Precht, assistant dean at the University of Michigan’s law school.

He said the eventual ruling on statements by an enemy combatant “is a test case for the government and the defense in terms of bringing these cases before civilian trials.

“If the government concludes it would jeopardize intelligence sources by going forward, and puts the case before a military tribunal, it may well be the death knell for other terrorism cases” in civilian courts.

Moussaoui is the only person charged in the United States as a conspirator in the Sept. 11, 2001, attack on the World Trade Center towers and the Pentagon. The Justice Department is seeking the death penalty for Moussaoui, a French citizen.

Moussaoui has acknowledged membership in al-Qaida but has denied participation in the Sept. 11 attacks.

Authorities believe Binalshibh was a key figure in the Hamburg, Germany, terrorist cell that carried out the suicide attacks.