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 the judge could consider whether the military commission system is legal, Hamdan's trial may 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.

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.

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.