Military lawyers are seeking to delay the arraignment of five Guantanamo detainees suspected of mounting the Sept. 11 terrorist attacks, alleging the government has made it impossible to defend them, authorities said Monday. The motions - four were filed in a flurry on Monday and one on Friday - attempt to postpone the first pretrial hearings for men charged with the 2001 attacks that killed almost 3,000 people in New York, Washington and Pennsylvania. The arraignment is scheduled for June 5 at the remote US Navy base in Guantanamo Bay, Cuba. The US is seeking the death penalty for all five defendants. A postponement would likely mean the hearing would not come until after the Supreme Court rules on the Bush administration's latest attempt to try terror suspects in the first US war-crimes trials since World War II. The Court declared a previous military tribunal system unconstitutional in 2006. It is expected to decide by the end of June whether the 270 men held at Guantanamo have access to regular US courts, which could undermine the military trials. Attorneys for the five men charged in the Sept. 11 attacks, including confessed mastermind Khalid Sheikh Mohammed, filed motions to delay their arraignment, Joe DellaVedova, a spokesman for the war-crimes tribunals, told The Associated Press. Two military attorneys for Ramzi Binalshibh, who allegedly served as the main intermediary between the Sept. 11 hijackers and al-Qaida leaders, said they are working in "an extremely challenging environment." Navy Cmdr. Suzanne M. Lachelier and her assistant counsel said flights to Guantanamo are limited and that, because all information they obtain from Binalshibh is "top secret," their notes can be kept only in a room without computers at the office of the chief defense counsel in Arlington, Va. "Counsel have no means of taking the notes back with them to their offices in Arlington, Va.; detailed counsel are unable to work with the notes in their offices on-board Guantanamo Naval Station; and counsel cannot even confer with each other about any discussions had with any 'high value' detainee, unless they return to Arlington, Va.," their motion said. Prosecutors have until May 25 to declare to the judge, Marine Col. Ralph Kohlmann, whether they oppose the motions. Defense lawyer and Army Maj. Jon Jackson said his team does not have enough access to his client, Mustafa al-Hawsawi, or to secure facilities where classified material must be reviewed. Al-Hawsawi, a Saudi, is accused of helping the Sept. 11 hijackers obtain money, clothing, traveler's checks and credit cards. Jackson said he has met his client only twice. According to a copy of the motion provided to the AP, Jackson has been barred from discussing those meetings with his assistant defense counsel, Navy Lt. Gretchen Sosbee, because the military has not yet given her security clearance. Sosbee accompanied Jackson to Guantanamo last week but was prevented from seeing al-Hawsawi, he said. Furthermore, the defense has not received any potential evidence against al-Hawsawi supporting charges that "allege a complex conspiracy spanning several years," Jackson told the judge. Defense lawyers are also crippled because they have been assigned no authorized location, at Guantanamo or in Washington, to review classified information, Jackson said in his motion. "Counsel have no place to store work product, discuss classified material or prepare for their case while in Cuba," Jackson wrote, adding that construction of a secure facility in Washington - which was to have been completed by the end of 2007 - has not even begun. DellaVedova insisted that defense lawyers have secure facilities at Guantanamo and in Washington to review the information. Jackson asked the judge to delay his client's arraignment until the government provides a security clearance for Sosbee, supplies the defense team with secure facilities for classified material and allows "for defense preparation of this case." More time is also needed to obtain a civilian attorney for al-Hawsawi if he wants one, Jackson said.