Johnny Adair is likely to know within several weeks whether the Northern Secretary's decision to return him to jail will be upheld.
The Shankill-based UDA commander will apply to the Sentence Review Commission to consider Mr Mandelson's suspension of the licence under which he was granted early release from the Maze prison 11 months ago. This accelerated procedure will take weeks, according to the commission's secretary, Dr Murray Power.
Adair is also planning to mount a separate judicial review of the move to suspend his licence on the grounds that Mr Mandelson believed he had broken its conditions. Should Adair's appeal to the commissioners and his judicial review fail, he will serve the outstanding period of his 16-year sentence, and will not be eligible for release until May 2002.
In such circumstances, he has the final option of reapplying to the Sentence Review Commission for further early release under the terms of the Belfast Agreement.
Mr Mandelson said last night that he had "hard information" from the RUC and other security forces which "persuaded me that he [Adair] had contravened the terms of his early release".
He said the case against Mr Adair was "strong and very solid" and he was not simply reacting to public pressure.
The law permits Mr Mandelson to suspend a prisoner's sentence if he "feels the person concerned has broken, or is likely to break, the licence conditions".
These conditions are that the released prisoner:
Does not support specified terrorist organisations not aligned to the peace process
Does not become concerned in the commission, preparation or instigation of acts of terrorism connected with the affairs of Northern Ireland, and
In the case of life prisoners, does not become a danger to the public.
Mr Mandelson said Adair had become concerned in the commission, preparation or instigation of acts of terrorism. Adair is the second paramilitary prisoner to be sent back to prison and have his licence suspended, but the first to seek to appeal the move.
Mr Mandelson has served Adair written notice of the reason for the suspension of his licence and Adair will respond to this in a written submission.
A three-member panel of commissioners will then consider both sides and deliver a preliminary written judgment.
If this is challenged by either side, a private oral hearing will take place. Adair can apply for legal advice during this hearing, after which the commissioners will give their final decision.
This can be further challenged by either side through a judicial review in the High Court.
The chairman of the UDP which has links with the UDA, said last night that Adair was "absolutely determined" to mount a judicial review action against Mr Mandelson's decision.
"He feels he's been made a scapegoat. Johnny Adair lives a charismatic life, verging on flamboyancy, but he has done nothing illegal," he said.
"He feels he's been blamed for a lot for which he has not been responsible. He's got the blame for everything."
Mr Adair met his lawyers in Maghaberry yesterday to discuss his legal options.