The Special Criminal Court will rule on Friday whether it will consider the opinion evidence of a political scientist who told the trial of Lisa Smith that anyone who travelled to Syria to support the Islamic State was a member of the terrorist organisation Isis.
Lawyers for Ms Smith have argued that the opinion evidence is not admissible and should not be considered as evidence by the three judges of the non-jury court.
Mr Justice Tony Hunt, presiding, said the court will deliver its judgement on the legal issue on Friday.
Ms Smith (40), from Dundalk, Co Louth travelled to Syria after terrorist leader Abu Bakr al-Baghdadi called on all Muslims to travel to the Islamic State.
She has pleaded not guilty to membership of an unlawful terrorist group, Islamic State, between October 28th, 2015 and December 1st, 2019.
She has also pleaded not guilty to financing terrorism by sending €800 in assistance, via a Western Union money transfer, to a named man on May 6th, 2015.
Dr Florence Gaub, a director with the European Union Institute for Security Studies, has told the trial that the Islamic State or caliphate announced by al-Baghdadi was the same thing as the terrorist organisation Isis and that a person became a member of Isis when they joined the state "actively with any type of act of support".
Such support, she said, could be a tweet, sending money, joining Isis-controlled territory or carrying out a terrorist attack.
