The Bush administration asked the Supreme Court yesterday to turn away a challenge to the military commissions the administration created to try some detainees at Guantanamo Bay on war- crimes charges.

Lawyers for Salim Ahmed Hamdan are seeking Supreme Court review of an appeals court decision in which Judge John G. Roberts Jr. sided with the other two judges in favor of the Bush administration.

In its brief to the Supreme Court, the Justice Department said the trial of Hamdan, a Yemeni who once was a driver for al Qaeda leader Osama bin Laden, should be allowed to proceed and said he will have ample opportunity later to raise any legal objections. Even if acquitted at trial, he will still be detained as an enemy combatant, the department said.

Hamdan's lawyers object to the possibility of classified documents being introduced against him at trial without his having access to them.

It is possible that no classified material would be presented by the prosecution, the government said in asking the Supreme Court not to hear Hamdan's case.

The Justice Department pointed out that the Pentagon relaxed the rules for tribunals a week ago, enabling classified information to be shared with defendants "to the extent consistent with national security, law enforcement interests and applicable law."

The rewritten rule also bars the admission of classified information if it "would result in the denial of a full and fair trial."

The rule changes also mean that the makeup of Hamdan's tribunal is likely to change, overcoming another of his objections, said the Justice Department.

Hamdan was not allowed to be present when his lawyers challenged the impartiality of the U.S. military officers hearing his case.

Under the new rules, the presiding officer is more like a judge in a court-martial or civilian court and is required to rule on all questions of law. The other members of the commission will function more like a jury and will no longer participate in deciding most legal questions.

The shift in responsibilities is likely to result in the replacement of the other members of the commission. They were the ones challenged by Hamdan's lawyers, so Hamdan's not being allowed to be present when their impartiality was called into question is no longer an issue, the department said.