Lawyers for Australians held by the US in Cuba have hailed a US Supreme Court's ruling that inmates should be allowed to challenge their detention.
David Hicks was captured in Afghanistan in 2001
Terror suspects David Hicks and Mamdouh Habib have been held for two and a half years at Guantanamo Bay naval base on the US-controlled part of the island.
Lawyers for the two men said they would launch an appeal.
The BBC's Rob Watson says this must be the biggest legal setback to President Bush since his war on terrorism began.
By a margin of six to three, the Supreme Court decided that the hundreds of prisoners being held at Guantanamo Bay did have a legal right to challenge their captivity.
The ruling passes no judgment on the guilt or innocence of those being held, but it does open the possibility that hundreds of appeals will now be launched in US courts on behalf of the detainees.
David Hicks, detained in Afghanistan while allegedly fighting alongside the Taleban, is due to face a US military commission on charges of conspiracy, attempted murder and aiding the enemy.
"Essentially everything that now happens within the commission will be subject to potential challenge in the US courts," said Stephen Kenny, a lawyer for Mr Hicks.
"It also means that the military authorities no longer have a place where they can treat people as they wish."
His Pentagon-appointed lawyer, Major Michael Mori, when asked if he would appeal replied: "Oh, certainly, if it's in David's best interests we will pursue whatever."
A lawyer for Mr Habib, Stephen Hopper, said an action would be launched to "challenge the merits" of the detention of his client, seized in Pakistan.
Australian Prime Minister John Howard said that the ruling would not affect his government's position that the two detainees should be prosecuted.
"My understanding is that the American Supreme Court has ruled that the detention has been lawful and that it's lawful not only in relation to American citizens but also in relation to foreigners," he said.
'Victory for justice'
Monday's ruling has also been hailed by US civil rights bodies as well as campaigners for British and other citizens among the detainees.
The ruling represented "a repudiation of the position of the government that they could have a lawless zone where they could do what they wanted to", said Jeffrey Fogel, legal director of the Centre for Constitutional Rights.
Kristine Huskey, a lawyer for Kuwaiti families involved, said they were "just thrilled" to see justice done.
"The Supreme Court has reaffirmed [the principle] that no executive branch is infallible and that it must be subject to judicial review," she said.
Azmat Begg, father of UK detainee Moazzam Begg, told BBC News Online he would take legal action against his son's continuing detention if he was not released.