Shankill Road UDA commander, Johnny Adair, will today begin his legal battle against the British government's decision to return him to jail.
Lawyers for Adair will argue against his imprisonment at Belfast High Court. They are attempting to overturn the decision taken by the Northern Secretary, Mr Paul Murphy, last Friday.
Mr Murphy said that, after studying a dossier compiled by the security forces, he believed Adair was too dangerous to remain at liberty and was likely to commit further offences.
The intelligence files have not been made public but they are believed to claim that Adair is heavily involved in terrorism, drug-dealing, extortion and money-laundering.
The UDA commander, who was granted early release in 1999 under the terms of the Belfast Agreement, was originally sentenced to 16 years imprisonment in 1994 for directing terrorism. If his legal battle fails, he will remain in jail until at least 2005.
The Shankill Road-based 'C' Company, which Adair leads, has been involved in an internal feud with the UDA leadership for several months. Five people have so far been killed during the feud.
Adair's close associate, Mr John White, said his return to jail was a political decision that had no legal justification. "We think it is wrong that a politician can have the power to return someone to prison.
"We will be asking what evidence he has and arguing that it is no longer acceptable that evidence can be given in camera." Mr White said that if today's legal challenge failed, Adair's lawyers would then seek leave for a judicial review of the decision.