A LEGAL challenge to the Special Advisers Bill is almost certainly doomed to fail, a leading human rights lawyer believes, unless Sinn Fein's Paul Kavanagh is willing to show remorse for his acts, and assist any police investigation.
"This legislation looks fireproof; a court challenge is unlikely to succeed," said Brice Dickson, Professor of Comparative and International law at Queen's University in Belfast.
Professor Dickson is also a former Chief Commissioner at the Human Rights Commission and the author of several textbooks on human rights law.
The bill prohibits people sentenced to five or more years in prison from working as special advisers – Spads – at Stormont.
It now looks like the only way the former IRA bomber can hang on to his job is by showing "contrition" and assisting the police investigation into his acts.
Prof Dickson has examined the legal arguments made by Sinn Fein and reviewed the legislation.
Sinn Fein argued that sacking Mr Kavanagh would impose a new penalty on him for his bombing offences. They see this as contravening the European Convention of Human Rights.
"I don't think this argument will fly," Professor Dickson told the Belfast Telegraph. "As the convention has drafted and has been interpreted by the European Court losing your job is not a legal penalty. In this particular situation, victims' interests are at stake."
Another possible grounds for challenge would be the Fair Employment and Treatment Order of 1998 which prohibits discrimination on grounds of political belief.
"That has been tested in the House of Lords already and it was found that having a belief in the use of violence for political ends is not a political opinion that is protected by law," he said.
He cited the case brought by two former republican prisoners who, like Mr Kavanagh, had been released early under the Good Friday Agreement (see panel).
The Law Lords accepted that neither of them now approved of violence. Yet the finding, summarised in the Times Law reports, was that "an employer in Northern Ireland could refuse to employ a person on the ground of his having supported the use of violence for political ends connected with the affairs of Northern Ireland even if the job-seeker had since repudiated such views."
Prof Dickson believed that the fact that the Spads bill contained an appeals mechanism makes a legal challenge more difficult and also provides one possible way forward for Mr Kavanagh.
He stated: "The courts are unlikely to say it is wrong to impose an obligation to assist the authorities in the detection of crime."
He believed that Mr Kavanagh could test the appeals conditions by publicly regretting the suffering caused. He could also name other people who have been convicted, such as Thomas Quigley, who was his accomplice in a 1981 bombing campaign in London.
"If he was unable to recall any other information which would assist the police that might work, why doesn't he test it?" Prof Dickson asked.
John McConkey and Jervis Marks were convicted respectively of murder and conspiracy to murder. Both rejected violence but were refused jobs by Simon Community. The Lords found against them in 2009, saying: "Any reference to a person's political opinion does not include an opinion which consists of or includes approval or acceptance of the use of violence for political ends."