Less than a week after he was jailed for life over the attacks on New York on September 11th 2001, Moussaoui submitted a motion asking to withdraw his guilty plea so he could be tried again.
"Moussaoui wishes to withdraw his guilty plea because when he entered the plea his 'understanding of the American legal system was completely flawed'," his lawyers said in the motion.
Moussaoui said in an affadavit "I now see that it is possible that I can receive a fair trial" in the United States.
"Even with Americans as jurors," he went on, "I can have the opportunity to prove that I did not have any knowledge of and was not a member of the plot to hijack planes and crash them into buildings on September 11, 2001."
"I wish to withdraw my guilty plea and ask the court for a new trial to prove my innocence of the September 11 plot," he said.
But Judge Leonie Brinkema said federal law prevented a guilty plea being changed once a sentence has been imposed. "His motion is too late and must be denied on this basis alone," Mr Brinkema said.
A jury rejected prosecutors’ calls for the death penalty last Wednesday.
They called for the 37-year-old Frenchman to be jailed for life without chance of parole after he admitted six charges of conspiracy over the September 11 attacks.
Moussaoui said he decided on Friday, while waiting to be transferred to a super-maximum security prison in Colorado, that he wanted to change his plea.