WASHINGTON — Court rulings on Thursday cleared the way for the first trial at the American detention camp in Guantanamo Bay, Cuba, opened in 2002 to hold suspects captured in the campaign against terrorism.

The trials have been delayed for years, in part by courts that found legal fault with the commissions created to try people designated by the government as "unlawful enemy combatants."

The rulings in Washington and in Guantanamo Bay rebuffed last-minute pleas by lawyers for Salim Hamdan, Osama bin Laden's former driver who is accused of being a member of al-Qaida.

Judge James Robertson, of U.S. District Court in Washington, ruled that Hamdan's claims that the military commission he faces is unconstitutional can be appealed to a civilian court only after his military trial is completed. In a parallel proceeding at Guantanamo, a military judge, Capt. Keith J. Allred of the Navy, rejected similar arguments.

After the rulings, the chief military prosecutor at Guantanamo, Col. Lawrence J. Morris of the Army, said prosecutors were "pleased by the court's ruling and we're ready to go to work."

Defense lawyers had hoped that the Supreme Court ruling last month in Boumediene v. Bush, upholding the right of Guantanamo prisoners to challenge their detention in court, might sway Robertson to halt the military trial.

Court officials at Guantanamo said they were planning on Saturday to assemble a panel of military officers — a military style of jury — to hear the Hamdan trial, which could begin Monday.

Morris called Hamdan's case an important test of the military commission system and said trials for others among the 20 detainees now charged would now move quickly. He predicted that the unfamiliarity of military commissions would quickly wear off, comparing them to space shuttle flights that once riveted public attention but became so routine that they attracted only modest interest.

It was Robertson who ruled in 2004 that the original procedures set for military commissions by President Bush were inadequate, a finding upheld by the Supreme Court. In response, Congress in 2006 passed the Military Commissions Act, setting up new procedures for the trials.

On Thursday, Robertson said the congressional action was sufficient to permit the trial. "Hamdan is to face a military commission designed by Congress under guidelines laid down by the Supreme Court," he said. He suggested that serious constitutional questions about the military commissions remain, but that they would have to be considered on appeal after Hamdan's trial.