Moussaoui was charged on 11 December, 2001, and this latest shift comes after the Justice Department decided not to oppose a defence motion to dismiss the case as a sanction for the government's refusal to allow Moussaoui access to witnesses.
The Justice Department reasoning was that a dismissal may be a way to get an appeals court to consider whether access to witnesses deemed enemy combatants by the US should be permitted.
A dismissal of the charges against Moussaoui doesn’t mean he’ll be freed.
Access to witnesses
Prosecutors have asked that if the charges are dropped, Moussaoui's release would be delayed while the issue of access to witnesses is appealed.
"The court has the authority ... to sometimes modify the rights of a defendant to get everything he wants"
Ex-assistant Attorney General
Prosecutors argue that Moussaoui planned to hijack a plane and crash it into the White House.
Judge Leonie Brinkema is under an immense amount of pressure from the Justice Department as they had counted on the tough reputation of the Alexandria court to get Moussaoui convicted and sentenced to death.
Still, Brinkema has ruled already that Moussaoui should be allowed to question three members of al-Qaida held at undisclosed locations by the United States. Moussaoui, who is acting in his own defense, says their testimony will exonerate him.
The judge has accepted in principle testimony from Khalid Shaikh Muhammad, considered al-Qaida's number three official, captured last March in Pakistan, and Mustafa Ahmed al-Hawsawi, allegedly involved in financing the operation.
She is also expected to soon decide whether Moussaoui can question alleged terror chief Hambali, arrested 11 August in Thailand.
US prosecutors remains adamantly opposed to such a move.
"The court has the authority ... to sometimes modify the rights of a defendant to get everything he wants" ex-assistant Attorney General Michael Chertoff, said recently, explaining prosecutors' opposition.
Brinkema ruling could come next week, a court source said.