Bradley Manning, the U.S. intelligence analyst charged with leaking thousands of classified U.S. government cables to the anti-secrecy group WikiLeaks, will face a court martial on September 21, a military judge said on Wednesday.

Manning faces 22 charges, the most serious of which could land him in prison for life, for downloading more than 700,000 classified or confidential files from the military while serving in Iraq in what has been the largest leak of classified documents in U.S. history.

In a blow for the 24-year-old, military judge Colonel Denise Lind ruled against a motion filed by Manning's lawyer to dismiss all the charges because of what he called the prosecutor's intentional withholding of evidence needed to prepare Manning's defense, and set a tentative trial schedule for September 21 through October 12.

Manning's trial will take place more than two years after he was arrested.

The court finds no evidence of prosecutorial misconduct, Lind said in a pre-trial hearing.

Military prosecutors have argued that they are meeting their obligations to hand over evidence to Manning's lawyers and that there is still time to provide the material to Manning before the trial begins.

Manning, in a dark military dress uniform and black-rimmed glasses, listened intently as the judge read out her rulings.

A handful of supporters of Manning, who view him as a whistleblower, sat in pews behind Manning. Lind instructed them to hold back from making noises during court proceedings after one guffawed at the judge's ruling.

In the second of three days of pre-trial hearings, Lind also denied a defense motion for a transcript or audio file of a grand jury in Alexandria, Virginia that has been investigating WikiLeaks founder Julian Assange, but ordered the testimony be examined for material relevant to Manning's defense.

Manning's attorney David Coombs was expected to call on the court to dismiss the charge that Manning aided the enemy, arguing that the charge is too broad and violates his client's right to free speech, according to a post on his blog.

Coombs said that under the government's interpretation the charge would apply to anybody who knows that information they publish or provide to be published could be accessed by the enemy.

The amount of conduct that is made subject to potential capital punishment under such an interpretation is staggering, Coombs wrote.

Aiding the enemy is a capital offense but the prosecutor has said it would not seek the death penalty in Manning's case.

Manning is accused of downloading files from the military's Secret Internet Protocol Router Network, or SIPRNet, while serving in the Army's 10th Mountain Division in Iraq.

(Reporting By Lily Kuo; Editing by David Storey and Vicki Allen)

Iraq Julian Assange Wikileaks