A U.S. military judge has refused to dismiss charges against an Army intelligence analyst accused of leaking secret documents to the website WikiLeaks.

Colonel Denise Lind, denied a motion to dismiss charges against Bradley Manning and tentatively set his court-martial to start September 21.

Lawyers for the U.S. Army intelligence analyst argued the case should be dismissed at a pre-trial hearing on Tuesday. They said prosecutors failed to meet their obligations to share information that could help the defense.

Manning has yet to enter a plea to 22 charges, the most serious of which is “aiding the enemy.”

Manning's lawyers are filing a specific challenge to the “aiding the enemy” charge. Attorney David Coombs wrote in a defense motion that his client “expressly disclaimed any intent to help any enemy of the United States” in online chat logs.

Manning is alleged to have leaked thousands of diplomatic cables and military documents related to Iraq and Afghanistan. If found guilty, he could spend the rest of his life in prison.

The pre-trial hearing at Fort Meade in the eastern U.S. state of Maryland is expected to last through Thursday.

Prosecution experts testified during a preliminary hearing in December they found evidence Manning downloaded diplomatic cables onto compact discs that were sent to WikiLeaks.

Manning's lawyers have described their client as a troubled man who should not have been allowed access to classified material while serving in Iraq between November 2009 and May 2010. His attorneys also said the military's oversight of its computers was lax.

The leaked documents, published by WikiLeaks starting in July 2010, infuriated many in the international community, often providing blunt and unflattering U.S. views of world leaders' private and public lives.

U.S. officials say the WikiLeaks publication of the stolen documents put lives in danger, threatened national security, and undermined American efforts to work with other countries.