The Supreme Court on Thursday delivered its third consecutive rebuff to the Bush administration's handling of the detainees at Guantánamo Bay, ruling 5 to 4 that the prisoners there have a constitutional right to go to federal court to challenge their continued detention.

The court declared unconstitutional a provision of the Military Commissions Act of 2006 that, at the administration's behest, stripped the federal courts of jurisdiction to hear habeas corpus petitions from the detainees seeking to challenge their designation as enemy combatants.

Writing for the majority, Justice Anthony M. Kennedy said the truncated review procedure provided by a previous law, the Detainee Treatment Act of 2005, "falls short of being a constitutionally adequate substitute" because it failed to offer "the fundamental procedural protections of habeas corpus."

Justice Kennedy declared: "The laws and Constitution are designed to survive, and remain in force, in extraordinary times."

The decision, left some important questions unanswered. These include "the extent of the showing required of the government" at a habeas corpus hearing in order to justify a prisoner's continued detention, as Justice Kennedy put it, as well as the handling of classified evidence and the degree of due process to which the detainees are entitled.