David Coombs, Manning's lawyer, said that holding him in maximum custody over the last five months and placing him on suicide watch amounted to abuse. Coombs called for his removal from such tight monitoring.
The complaint was filed on Wednesday and on Thursday the marines downgraded his classification from suicide watch to prevention of injury. But Coombs argues that prevention of injury is not significantly different in practical terms and is seeking his removal from maximum security.
Coombs, writing on his office website, said that on Wednesday, against the recommendation of two forensic psychiatrists, the commander of the Quantico jail, James Averhart, listed Manning as a suicide risk, which meant he was confined to his cell 24 hours a day. "He was stripped of all clothing with the exception of his underwear. His prescription eyeglasses were taken away from him. He was forced to sit in essential blindness with the exception of the times that he was reading or given limited television privileges. During those times, his glasses were returned to him," Coombs wrote.
Manning, aged 23, who had been based in Iraq, was transferred to Quantico on July 29 last year. He is facing court-martial later this year and faces a heavy prison sentence if found guilty of leaking classified material.
Coombs said that the downgrading of Manning from suicide watch to prevention of injury does not make much practical difference and that he remains under close scrutiny.
The guards check him every five minutes during the day and Manning is required to respond, Coombs said. "At night, if the guards cannot see him clearly, because he has a blanket over his head or is curled up towards the wall, they will wake him in order to ensure that he is okay," Coombs said.
He is not allowed to do exercises in his cell, only during the one hour a day when he goes from his cell to an empty room with some gym equipment.
First Lieutenant Scott Villiard, a spokesman for Quantico, told the Washington Post: "The most important thing is that we're not treating Private Manning any differently from anyone else that would be in the same classification. Whether it's maximum custody or prevention of injury, he's being treated the same as anybody else."
There was "a responsibility to make sure that these detainees are safe, secure and make it to trial," Villiard said. Manning had been placed in maximum custody because, the authorities said, his escape could pose a risk to life, property or national security.