Seventeen Chinese prisoners who have been held for nearly seven years in Guantánamo Bay will be informed on Monday that they could spend the rest of their lives behind bars, even though they face no charges and have been told by a judge they should be freed.

No country is willing to accept them and the US justice department has now blocked moves for them to be allowed to go to the US mainland, where they had been offered a home by refugee and Christian organisations.

The men's lawyer, Sabin Willett, is flying to Guantánamo Bay this weekend to break the news to the men, who are members of the Uighur ethnic group seeking autonomy from China. In a blunt and angry letter to justice department lawyers, Willett spelled out what he thought of the way the men had been treated.

"After years of stalling and staying and appellate gamesmanship, you pleaded no contest - they are not enemy combatants," Willett has written. "You have never charged them with any crime."

Last month a federal judge ruled that the men should be freed. "They were on freedom's doorstep," said Willett. "The plane was at Gitmo. The stateside Lutheran refugee services and the Uighur families and Tallahassee clergy were ready to receive them." However, the justice department appealed against the ruling and Willett claims this will put the men into a potentially endless limbo.

Yesterday Willett said his clients were "saddened" by the latest events. The men, who are Muslims, were in Afghanistan in 2001 and were captured by Pakistani troops and handed over to the US. So far, more than 100 countries have been asked to take them as refugees but none have agreed. Willett blamed US authorities for incorrectly describing them as terrorists.

According to the US justice department, the men "are linked to an organisation that the state department has labelled to be a terrorist entity, and it is beside the point that the organisation is not 'a threat to us' because the law excluding members of such groups does not require such proof."

Willett is also angry the defence department will not agree to let him meet his clients unless they are chained to the floor. He called for this restriction to be lifted: "Just permit these men one shred of human dignity." He added: "Americans are not supposed to treat enemy prisoners of war this way under the service field manuals, or the Geneva conventions - if anyone paid attention to the field manuals or the Geneva conventions anymore."