Islamist preacher Abu Hamza's legal team is to appeal his extradition order from Britain to the United States.
British Home Secretary Jacqui Smith has signed the papers paving the way for Hamza (49) to face terrorist charges.
Muslim cleric Sheikh Abu Hamza al-Masri
But his lawyer, Muddassar Arani, confirmed an appeal would be mounted before the 14-day deadline.
"There are grave concerns about what might happen if the extradition goes ahead. The Americans have said he will not face the death penalty or be sent to the Guantanamo Bay detention camp - but how can we be sure? I also fear that if he was sent to America he would become a victim of torture."
Hamza, who has served two years of a seven-year sentence for soliciting murder and inciting racial hatred, will face charges in the United States
that include providing support to al-Qaeda and involvement in a hostage-taking conspiracy in Yemen.
The US government claims he was involved in a global conspiracy to wage jihad against the it and other western countries.
He is accused of involvement in the kidnapping of western tourists in Yemen, helping to set up a terrorist training camp in the United States and funding the trip of a would-be jihadist to a terrorist training camp in the Middle East.
He is wanted on 11 US charges and could face up to 100 years in jail if convicted.