Lawyers for the three Irishmen sentenced to up to 17½ years by a Colombian court last week said yesterday they were "exploring every legal option left open to the three men".
They declined to say if they would take the case to the country's Supreme Court.
Niall Connolly and Jim Monaghan were sentenced to 17½ years each by the Bogota appeal court and ordered to pay fines of $245,000; Martin McCauley was sentenced to 17 years and his fine was set at $212,000. The men were arrested in August 2001 and charged with training rebels from the Revolutionary Armed Forces of Colombia (FARC), in urban terrorism and weapons-making techniques.
Reading from a prepared statement at the lawyers' offices, Ms Caitríona Ruane, a spokeswoman for the Bring Them Home solidarity campaign, called last week's ruling which overturned a lower court ruling in April acquitting the men, "a political decision". She added: "We are planning to bring the case of these Irishmen and EU citizens to the European Parliament. This campaign will continue and intensify".
Ms Ruane said she did not know where the men were: "I last saw them 6½ months ago when we accompanied them out of the prison. Since then neither their lawyers, their families, nor the Bring Them Home campaign have had any contact with them."
Two of the three lawyers representing the men were present with Ms Ruane.
Mr Pedro Maecha, the lawyer for Mr Monaghan, said the ruling was, "blind to the major contradictions of the prosecution witnesses and provides excuses for incorrect dates given for the men being in Colombia".
"It makes judgments against the three men using laws that were not even introduced at the time," he said.
Mr Maecha also said that in the 144 pages of the appeal court ruling, only a few pages were given over to the defence lawyer arguments. He said: "The document focused heavily on the prosecution arguments.
"All the evidence presented to the court favours the three men. This judgment violates fundamental legal principles and rights". He called the ruling "a slap in the face for Colombian and international justice".
Mr José Luis Valasquez, who represents Mr McCauley, said the appeal court decision "failed to take into account evidence from credible defence witnesses, for example, the declaration of Irish diplomat Ms Síle Maguire, who was an alibi witness for the defence".
In the event of the case going to Colombia's Supreme Court, legal experts say it could take several years to come to a verdict because of the backlog of cases.
Ms Ruane said she would remain in the country for a few more days while she analysed all options with the men's lawyers.