Human rights judges will rule tomorrow on whether to allow the government to extradite radical preacher Abu Hamza to America to face terrorist charges.
The Muslim cleric, serving a seven-year sentence in Britain for soliciting to murder and inciting racial hatred, has become the focus of growing concern over human rights rulings from Strasbourg which ministers claim could compromise national security.
The European Court of Human Rights halted extradition proceedings in July 2010, arguing it needed more time to consider complaints that transferring Abu Hamza and others wanted in the US risked breaching their rights by exposing them to possible life imprisonment without parole and solitary confinement.
Tomorrow the judges will give a final ruling on six extradition cases in a verdict effectively passing judgment on whether America's treatment of terrorist suspects could amount to "inhuman or degrading treatment or punishment" in breach of the European human rights code.
Egyptian-born Abu Hamza was granted British citizenship in 1986. He is wanted in America on 11 charges related to taking 16 hostages in Yemen in 1998, promoting violent jihad in Afghanistan in 2001 and conspiring to set up a jihad training camp in Oregon, America.
The American authorities have described him as a "terrorist facilitator with a global reach".
But before the US extradition request could be dealt with, Abu Hamza had been convicted in 2006 of terrorist-related charges in Britain.
Among those facing extradition alongside him is Babar Ahmad, a 36-year-old computer expert who has been in a UK prison without trial for nearly eight years. He has been refused bail since his arrest in August 2004 on a US extradition warrant.
Both appealed separately to the European Court of Human Rights on the grounds that their treatment and potential punishment could violate Human Rights Convention Article 3 banning torture and "inhuman or degrading treatment".
The fate of four other British nationals wanted in the US - Haroon Rashid Aswat, Seyla Talha Ahsan, Adel Abdul Bary and Khaled Al-Fawwaz - is also being decided by the human rights court.
All six have been indicted on various charges of alleged terrorism in America and argue that, if extradited and convicted in America, their conditions of detention if held at one of the country's so-called "supermax" prisons would amount to ill-treatment under Article 3 of the Human Rights code.
In July 2010 the human rights judges said they needed more time to consider whether the Eighth Amendment to the US Constitution - a ban on "cruel and unusual punishment" - gives the equivalent protection to Article 3 of the European code which states: "No-one shall be subjected to torture or to inhuman or degrading treatment or punishment".
Babar Ahmad and Ahsan are accused in America of providing support to terrorists and conspiracy to kill, maim or injure people and damage property in a foreign country. Aswat is accused of conspiring with Abu Hamza to establish a jihad training camp in Oregon.
One issue the Strasbourg court has been considering is whether the American principle of life imprisonment without parole breaches the European human rights code.
In January the same court refused to allow the UK to deport Abu Qatada to Jordan, where he is wanted on terrorist charges, without assurances that evidence gained through torture would not be used against him at his trial.
The result caused Government fury, and has still not been resolved: last month Home Secretary Theresa May went to Jordan, returning after "positive" talks, but with no firm assurances to take back to the human rights court.