Their anger follows a US court of appeal's reversal of extradition proceedings against the trio, to give them a chance to clear their names.

Artt: Murdered off-duty prison officer

Kevin Barry Artt and Terence Kirby, who were both jailed for murder, and Paul Brennan, who was convicted of possessing explosives, had faced a return to prison in the UK.

The three men were among 38 inmates who broke out of the Maze Prison in September 1983.

Tom Coulter: "The American appeal court's decision has angered Unionists"

They have been living in California ever since.

But the Ninth US Circuit Court of Appeals in San Francisco reversed a federal judge's extradition order on Friday.

Kirby: Murdered petrol station attendant

And it is to take a closer look at whether the three were treated unfairly during legal proceedings in Britain in the 1980s.

"It's a big victory. It's like a Celtic Amistad for us," said Artt's lawyer, Jim Brosnahan, who called for Britain to drop its case against the men completely in line with the spirit of the Good Friday agreement.

But Ian Paisley Jnr, justice spokesman for the Democratic Unionist Party, said comparing the men to black slaves was an outrage.

"This is absolutely horrendous," he said.

Brennan: Posessed explosives

"What happened to American cooperation? It really is a disgrace.

"The American authorities are in breech of the spirit of the Good Friday agreement themselves by not following through on extradition proceedings."

Ulster Unionists security spokesman Ken Maginnis said: "It is unhelpful when an American court calls into question the integrity of a justice system which has served the people of Northern Ireland well during 30 difficult years."

Ken Maginnis: "US court decision unhelpful"

Artt was sentenced to life imprisonment for the 1978 murder of an off-duty deputy Maze Prison governor in Belfast, while Kirby was given life for the 1976 murder of a petrol station attendant.

Brennan was convicted of possessing explosives, which police said were to be used to blow up a store in Belfast for the IRA.

After escaping from the Maze, the three fled to California, where they found work and raised families before being ordered back to Belfast in 1992.

They sought to block extradition on the grounds that they would be persecuted because of their religion and republican sympathies.