AP

A military judge refused on Thursday to dismiss the most serious charge against an Army private accused in the biggest leak of government secrets in US history.

Col. Denise Lind rejected a defence motion to dismiss the charge of "aiding the enemy" during a pretrial hearing for Pfc. Bradley Manning. The charge carries a maximum penalty of life in prison. Manning also faces 21 other counts.

In seeking dismissal of the most serious offence, defence lawyer David Coombs had argued that the charge didn't properly allege that Manning intended to help al-Qaeda when he allegedly sent hundreds of thousands of classified Iraq and Afghanistan war reports and State Department diplomatic cables to the anti-secrecy website WikiLeaks.

Manning stated in an online chat with a confidant-turned-informant that he leaked the information because, "I want people to see the truth."

Prosecutors had argued that Manning knew the enemy would see the material when it appeared on WikiLeaks, regardless of his intentions.

Lind said on Thursday that prosecutors must prove during trial that Manning had knowledge he was giving information to the enemy. If they fail to do so, Lind said she would entertain further motions from the defence.

Manning hasn't entered a plea to any of the charges. He also hasn't yet decided whether he will be tried by a judge or a jury. His trial is set for Sept. 21 through Oct. 12.

Earlier Thursday, Lind rejected a motion to consolidate some charges that the defence said were duplicative. She said the defence could raise the motion again for sentencing purposes if Manning is convicted.

She denied another defence motion seeking to dismiss a count on the grounds that it was improperly charged. That count alleges that Manning wrongfully and wantonly caused intelligence to be published on the internet, knowing it would be accessible to the enemy.

Lind also heard arguments on a government motion to bar any discussion at trial of whether the leaked material harmed US interests. Prosecutor Maj. Ashden Fein said the government must prove only that Manning leaked the material knowing it could cause harm, regardless of whether it did.

The motion appeared to be aimed at blocking the defence's attempts to obtain classified reports compiled by the departments of Defence, State and Justice assessing the damage done by the WikiLeaks disclosures. Defence lawyer David Coombs said the reports probably say the leaks did little or no damage; otherwise, he said, the prosecution would be eager to discuss them.

Fein said that since the government doesn't have to prove damage, any courtroom discussion of damage assessments would waste the court's time.

"Just because a damage assessment might say damage did occur or didn't occur, it's completely irrelevant" to proving the charges, Fein said.

The 24-year-old Oklahoma native was ordered court-martialed after he was accused of downloading the war logs, cables and video clips, and then sending them to WikiLeaks. He was working as an intelligence analyst in Baghdad when authorities say he copied classified material from government computers in late 2009 and early 2010.

The material WikiLeaks published included cockpit video of a 2007 US Apache helicopter attack that killed a number of civilians, including a Reuters news photographer and his driver. The US government says the civilian deaths were accidental.