The European Court of Human Rights gave final approval on Monday for the extradition of one of Britain's most radical Islamist clerics and four others to the United States, where they face terrorism charges.
The decision caps a long legal battle and means Abu Hamza al-Masri could be extradited within weeks. Britain's Home Office, or interior ministry, said it would hand over the suspects "as quickly as possible".
The Egyptian-born al-Masri, 54, filed an appeal, along with the four other suspects, after the court in Strasbourg authorized Britain to transfer him to the United States on charges he supported al Qaeda and aided a fatal kidnapping in Yemen.
Al-Masri, who could face a sentence of more than 100 years in an ultra-secure "Supermax" prison, had argued such treatment would contravene Article 3 of the European Convention on Human Rights, which prohibits inhumane and degrading treatment.
"Today the Grand Chamber decided to reject the request. This means that the Chamber judgment of April 10, 2012, is now final," the court said in a statement.
The decision also concerned appeals lodged by four other defendants, Babar Ahmad, Syed Tahla Ahsan, Adel Abdul Bary and Khaled Al-Fawwaz, all of whom have been detained in Britain pending extradition to the United States.
A Home Office spokesman said: "We will work to ensure that the individuals are handed over to the U.S. authorities as quickly as possible."
The family of Ahmad called on the government to halt the extradition process, saying British prosecutors were in possession of the material that forms the basis of the U.S. indictment and should pursue the case in Britain.
Al-Masri is one of the most radical Islamists in Britain, a country he has attacked for its support of U.S.-led wars in Iraq and Afghanistan.
The one-eyed radical with a metal hook for a hand who has praised the September 11, 2001 attacks, was once a preacher at a North London mosque but was later convicted of inciting murder and racial hatred. He is being held in a British jail.
He was indicted in 2004 by a federal grand jury in New York, accused of providing material support to al Qaeda and of involvement in a hostage-taking in Yemen in 1998 in which four hostages - three Britons and one Australian - were killed.
He was also accused of providing material support to al Qaeda by trying to set up a training camp for fighters in the Pacific state of Oregon and of trying to organize support for the Taliban in Afghanistan. (Reporting by Vicky Buffery in Paris and Alessandra Rizzo in London; Editing by Janet Lawrence)