The family of Ibrahim Halawa are to hold a news conference in Dublin on Friday to address further delays in their brother's case.
It follows Monday's announcement in Egypt of a three-week delay in the verdict of his long-running trial.
Taoiseach Leo Varadkar said earlier this week that he has been assured by the Egyptian president the case of Mr Halawa will be resolved swiftly once the verdict is known.
Mr Varadkar spoke with president Abdel Fattah Al-Sisi for 25 minutes on Monday evening.
The Taoiseach expressed his disappointment at the decision to delay the verdict for a further three weeks and made it clear his priority was to secure the return of Mr Halawa to Ireland as soon as possible.
President Al-Sisi insisted his Government could not interfere in a judicial process but stressed the matter would be dealt with swiftly once the trial was brought to an end.
Mr Halawa, from Firhouse in Dublin, was 17 when he and hundreds of others were arrested in August 2013 in Cairo during protests against the ousting of then president Mohamed Morsi of the Muslim Brotherhood.
He has been on trial with 493 others, but the process has been beset by delays, and substantive hearings have only taken place in the past eight months.
No evidence implicating Mr Halawa was presented to the three-judge court.
The judgment has been put back until September 18th.