FORT MEADE, Maryland — President Barack Obama's comments about the soldier accused of the biggest intelligence leak in US history may have damaged the prospects of a fair trial, a defense lawyer argued Tuesday.

Other leading members of the government, including Secretary of State Hillary Clinton and the former head of the US military, Admiral Mike Mullen, also made ill-advised remarks about Private Bradley Manning, a military court heard.

"Even though he is the commander-in-chief he does not have influence in this courtroom," civilian attorney David Coombs told Manning's pre-trial hearing at Fort Meade military base in Maryland, referring to Obama.

Manning, 24, could spend the rest of his life in jail if he is convicted of aiding the enemy by handing hundreds of thousands of classified documents to WikiLeaks, the file-sharing website.

The soldier was serving in Iraq as an intelligence analyst when he was arrested in May 2010 and accused of releasing thousands of classified military logs from Iraq and Afghanistan and State Department diplomatic cables.

Coombs told the hearing Obama's remarks -- made at a political fundraiser in California last April -- that Manning "broke the law," as well as statements from Clinton, Mullen and others on the matter were designed to damage his client.

These are "people who should know better," Coombs said. "Members of the government have taken the opportunity to throw comments out to the press that were very prejudicial. It was done purposefully and was unfortunate for us."

The massive document dump to WikiLeaks triggered a diplomatic firestorm that hugely embarrassed US officials and rankled allies.

The soldier has not yet entered a plea in the court-martial and his trial is tentatively due to start in September.

On Monday, the first day of the five-day pre-trial hearing, Manning's defense team argued that government lawyers must prove that the soldier intended to help Al-Qaeda by passing secret government documents to WikiLeaks.

The prosecution, however, has countered that they only have to prove that Manning knew Al-Qaeda might see the sensitive files posted by WikiLeaks, given his training as a military intelligence analyst.