[JURIST] Lawyers representing detainees held in the US prison camp at Guantanamo Bay [JURIST news archive] Wednesday petitioned [brief, PDF; second brief, PDF] the US Court of Appeals for the District of Columbia Circuit to declare a portion of the Military Commissions Act of 2006 (MCA) [PDF text; JURIST news archive] unconstitutional. A key provision in the act, which was signed into law [JURIST report] by US President George Bush last month, strips US courts of jurisdiction to consider writs of habeas corpus filed by detainees who are detained as enemy combatants [JURIST news archive]. The lawyers argued that the MCA as written still permits detainees who have not been charged to pursue habeas claims and that the US Constitution gives prisoners the right to challenge their detentions in civil court. After the measure was signed, the US Justice Department sent letters [JURIST report] to the DC district and appeals courts, notifying the lower court that it no longer had jurisdiction over some 200 pending cases filed by Guantanamo detainees, and urging the appeals court to reach the merits on two cases currently on its docket in light of the MCA. Wednesday's briefs were filed in the two appeals court cases. Reuters has more.

Joining in the challenge Wednesday were seven retired federal judges who in an amicus brief urged [brief, PDF] the appeals court to rule that portions of the MCA violate the Constitution. Judges from both political parties said the MCA's prevention of civil courts from hearing cases brought by uncharged detainees "challenges the integrity of our judicial system." The seven also said the Act does not adequately prevent the military's use of torture [JURIST news archive] since there is no "check" on suspect methods of interrogation without prisoners having the opportunity to use the courts to challenge alleged torture. The Bush administration has until November 13 to respond in the cases, which are expected to eventually reach the US Supreme Court. The high court previously ruled that the commissions, as initially constituted, lacked proper legal authorization [JURIST report], a decision that prompted the new legislation. AP has more. SCOTUSblog has additional coverage.