WikiLeaks suspect Bradley Manning challenged US prosecutors Wednesday to prove he intended to "aid the enemy" by turning over documents to the whistleblower website, arguing that spilling secrets could not be treated as a plot to help Al-Qaeda.

Manning's lawyer insisted at a pre-trial hearing that the government's case implied any soldier could be prosecuted for helping Al-Qaeda if they leaked sensitive information to an Internet site, including prominent newspapers.

If allowed to stand, the prosecution's definition of the offense would violate free speech rights and constitutional protections, said David Coombs, civilian counsel for Manning.

That interpretation of the law "would be alarming in its scope," he told the court.

The most serious charge facing the 24-year-old US Army private alleges he was knowingly "aiding the enemy" when he passed a massive cache of classified data to WikiLeaks. The charge can carry the death sentence, and prosecutors are seeking life in prison in this case.

To be convicted on the charge, Coombs said the government has "to show general evil intent" on Manning's part and not merely that "he should have known better," which the lawyer said would amount to a lesser charge of gross negligence.

Prosecutors, however, countered that Manning's intent was not the issue and that the government only needed to prove that the intelligence analyst knew Al-Qaeda would see the leaked the information on the WikiLeaks site.

"We're talking about knowingly giving information to the enemy by indirect means," prosecutor Captain Joe Morrow said.

The judge, Colonel Denise Lind, asked the prosecutor if a soldier leaking classified or sensitive details to a newspaper that the enemy might see on the Internet would be charged under the same offense, known as Article 104 in the military code.

The prosecutor said it would depend on the context of such a leak and that Manning represented a clear-cut case of someone directing information to a "specific website" with knowledge that it would reach "the enemy."

The court arguments came after Lind rejected a request to dismiss all charges against Manning, paving the way for him to be tried starting September 21 over the worst ever breach of US intelligence. The judge's decision was in line with analysts' expectations.

Manning's lawyers argued the government had consistently "stashed away" crucial information that could help their client mount his defense and demanded that all 22 counts against the army private be thrown out.

But Lind said that the court had found "no evidence of prosecutorial misconduct."

"The government properly understood its obligation" to share relevant information with the defense, she said.

Manning is accused of passing hundreds of thousands of military field reports from Iraq and Afghanistan and US diplomatic cables to WikiLeaks between November 2009 and May 2010, when he served as a low-ranking intelligence analyst in Iraq.

After failing to get the case thrown out, Coombs tried to limit his client's legal exposure by arguing for some counts to be discarded, saying prosecutors had imposed multiple charges for single criminal violations.

Manning has yet to enter a plea in the case after spending about 700 days in confinement.

The Welsh-born US army intelligence analyst was transferred a year ago from a military prison at Quantico, Virginia -- where he had been imprisoned since July 2010 -- to another in Fort Leavenworth, Kansas.

During Manning's eight months of solitary confinement at Quantico, he was subjected to "cruel, inhumane and degrading treatment," according to a UN special rapporteur.

The WikiLeaks document dump embarrassed the US government, and officials said the leaks threatened national security and the lives of foreigners working with the military and US embassies.

But WikiLeaks supporters view the site as a crusading whistleblower that exposed US wrongdoing, and portray Manning as a political prisoner.