9/11 trial lawyers seek Obama and Bush testimony
Lawyers for three men accused of plotting the 9/11 attacks want US President Barack Obama and predecessor George W Bush to give evidence.
The lawyers say the men cannot receive a fair trial after being regularly called "terrorists" and "murderers".
Ramzi Binalshibh, Mustafa Ahmad Al-Hawsawi, and Ali Abd Al-Aziz Ali will face a military trial at Guantanamo Bay and a possible death penalty.
The presidents are not expected to agree to give evidence.
The 11 September attacks killed 2,976 people in New York, Washington and Shanksville, Pennsylvania in 2001.
In a motion to dismiss the charges, the defence teams say the language used by the current and former presidents has exerted what is known in military law as "unlawful influence" on the case.
The BBC's Jonathan Blake, in Washington, says that the request highlights just one of several complicated issues that must be resolved before the case can begin and how difficult it has been for the US to bring people to justice over the 9/11 attacks.
"Under these facts, it is impossible for any objective, disinterested observer, with knowledge of all the facts and circumstances, to believe these men can receive a fair trial by military commission," the lawyers wrote.
"It can easily be understood by members of the public that this system of military commissions exists solely for the purpose of imposing a death sentence upon these accused."
The lawyers have also requested testimony from Vice President Joe Biden, Attorney General Eric Holder, South Carolina Republican Senator Lindsey Graham, who has been involved with detainee policy, as well as a number of Pentagon officials.
The motion was filed on 11 May but posted on a Pentagon website only on Wednesday after security clearance, is one of several pending pre-trial motions. Prosecutors have not responded to the motion.
In addition to the three men, Waleed bin Attash and Khalid Sheikh Mohammed, the self-described mastermind of the attacks, are also facing trial on charges of murder and terrorism.
They have not entered pleas on the charges.
In 2009, an effort to have them tried in a civilian court failed in the face of a public outcry and congressional opposition.
The five were eventually charged in June 2011 with offences similar to those they were accused of by the Bush administration.
One of the defendants' lawyers, James Connell, has predicted the trial would take years to complete.