SECRETARY of State Shaun Woodward is facing pressure to ask for the extradition of an IRA man involved in the 1983 Maze prison break in which a warder was fatally stabbed.
It emerged yesterday that Pl Brennan is to be deported from the US – where he has been living for 25 years – to the Republic.
Brennan, who escaped the Maze along with Sinn Fein's Gerry Kelly and 35 other IRA prisoners, lost a final attempt to stave off deportation and is expected to be flown to Shannon airport some time this week.
His wife, Joanna Volz, who said that her husband had an Irish passport, attacked the US authorities for "going against the spirit of the Agreement" in deporting him over an immigration offence.
But unionists said they were outraged at what appeared to be a tacit understanding that if Brennan remained south of the border he would not be re-arrested.
When contacted yesterday, Government departments and justice agencies on both sides of the border gave away little about what will happen to Mr Brennan on his return.
A Northern Ireland Office spokeswoman confirmed that there was no move to extradite Mr Brennan if he remained outside the UK but added: "Anyone who is unlawfully at large from prison in the UK is liable to be arrested."
A spokesman for the Public Prosecution Service said that the Brennan case was a matter for the PSNI.
A PSNI spokesman said that it was "aware of developments" and was "monitoring the situation".
The Irish Foreign Office said that the case was a matter for the Irish Justice Department.
But a spokeswoman for the Justice Department said that it "did not discuss individual cases".
Citing Brennan's terrorist conviction and the fact that in 1993 he was arrested and charged with possessing a firearm in the US, Lagan Valley DUP MP Jeffrey Donaldson said that his criminal record "would suggest that he may represent a public risk were he to return to Northern Ireland or even the Republic of Ireland".
"I am now publicly calling on the Secretary of State to set procedures in place for Brennan to be returned to jail," he said.
"He has a remaining sentence to be served for terrorist crimes and he committed another criminal offence whilst escaping from the Maze."
Mr Donaldson said that if Brennan returned to the Republic he would be writing to Irish Justice Minister Dermot Ahern "seeking his views on the matter and urging him to take action".
TUV leader Jim Allister said that Brennan remained a "fugitive from justice".
"If and when he arrives in the Republic it therefore behoves Her Majesty's Government to immediately proceed with a European Arrest Warrant and seek to have him extradited to Northern Ireland," he said.
"One cannot help, however, fearing that Brennan will be given a by-ball just like Pearse McAuley a few weeks ago."
Mr Allister also pointed out that Mr Brennan's fellow Maze escapee, Sinn Fein North Belfast MLA Gerry Kelly, now serves as a Junior Minister in the Office of the First Minister and Deputy First Minister at Stormont.
In a statement yesterday, Mr Kelly said that it was “desperately disappointing” that Brennan was to be deported and said that Sinn Fein had been “making representations on Pl’s behalf to the US authorities and we will continue to work with him and his family in the time ahead”.