Lawyers for Osama bin Laden's former driver asked a civilian judge Thursday to delay his military trial.

Salim Hamdan has been challenging the legality of the military commission system since 2004, but the case stalled as courts wrestled with the question of whether Guantanamo Bay detainees have the right to use civilian courts.

A recent Supreme Court decision gave Hamdan's case new life in a Washington federal courthouse, but by the time a judge could consider the legality of the military commission system, Hamdan's trial might already be over. It's scheduled to begin July 21.

His lawyers asked U.S. District Judge James Robertson to order the military to delay Hamdan's trial while he challenges his detention and the military commission process. Justice Department spokesman Erik Ablin said the department believes the military commissions are constitutional and "should go forward without interruption."

Hamdan, a Yemeni, faces up to life in prison if convicted of supporting terrorism. He is one of 19 Guantanamo prisoners with charges pending against him; the U.S. has said it plans to prosecute about 80. Robertson's decision will help determine whether the trials will go forward against the other detainees.

Robertson scheduled a hearing on the issue for July 17.

Hamdan's lawyers acknowledge he worked for bin Laden, but say he was just a minor employee with no significant role in terrorism. The government, however, says he was the terrorist leader's personal driver, helping him evade U.S. retribution following the Sept. 11 attacks.