Assigned by the military to defend the detainees, the lawyers significantly challenged both the detentions and the planned military trials.

"The constitution cannot countenance an open-ended presidential power, with no civil review whatsoever, to trying anyone the president deems subject to a military tribunal, whose rules and judges have been selected by the prosecuting authority itself," they said.

The lawyers described the continuing detention of 660 "terror" suspects without charge at Guantanamo Bay in Cuba as a "legal black hole."

The US has been holding them since 2001 as "enemy combatants", a designation which deprives them of protection afforded by prisoner of war conventions.

The lawyers urged the high court to reject the Bush administration's argument that Guantanamo detainees have no access to US civilian courts.

"If there is no right to civilian review, the government is free to conduct sham trials and condemn to death those who do nothing more than pray to Allah," the lawyers said.

Lawsuit

The Pentagon had no comment on the substance of the defence lawyers' argument.

"We have always said we expect them to be advocating for their clients," a Pentagon spokesman said.

A Guantanamo detainee on Wednesday sued President Bush and other government officials, seeking $1.1 billion in damages for what he said were violations of his constitutional rights.

Salim Ghiraibi alleged he was being held without legal basis and had been denied his freedom of speech, association, religion and other constitutional rights.

Ghiraibi's lawyer Stephen Yagman wants the lawsuit certified as a class action for all the Guantanamo prisoners.

Growing pressure

There is worldwide outrage over
the Guantanamo detentions

The Bush administration found itself under more pressure on the issue with 175 British legislators demanding the Guantanamo detainees should be granted access to US civilian courts.

"Its not about whether the people there are guilty or not. What's at stake is something far more important... whether the courts have a right to review what the president is doing," said a lawyer representing the legislators.

Speculation has been mounting of late that nine British citizens held in the camp are to be released shortly.

UK Home Secretary David Blunkett has reportedly ruled out placing the British detainees at Guantanamo under surveillance if they are repatriated.

The Daily Telegraph reported on Thursday that since there was no evidence to charge the nine British Guantanamo prisoners with any offence, they should be set free as soon as they landed in the UK.

The paper also quoted Blunkett as saying the Britons should either face a fair trial under US arrangements or "return to go about their business."

"I have never suggested that we can take action against them in this country without trial. Where there isn't evidence that would stand up in a British court, as opposed to a US military tribunal, then people can't be tried," the home secretary was quoted as saying.