Ibrahim Halawa has said that the past three weeks in a Cairo jail have been harder than the previous four years.
The 21-year-old from Dublin has been acquitted of all charges relating to mass protests in Cairo four years ago. but remains in custody.
Former justice minister Alan Shatter has said the Egyptian Ambassador to Ireland should be expelled if Mr Halawa is not released by the end of this week.
He said it is totally unacceptable and grossly unjust that more than three weeks after Mr Halawa was found not guilty he is still in a jail having been held there for four years with no evidence against him.
However, Fianna Fáil TD Darragh O'Brien said he believes expelling the ambassador would be a ridiculous move, which would not serve Mr Halawa or his family any good.
Labour leader Brendan Howlin said it is beyond the point of tolerance that an Irish citizen found innocent should remain in custody after four years.
He was part of a delegation that visited Mr Halawa in jail in Egypt earlier this year.
In a statement, Mr Howlin said that while it was explained to them by Egyptian authorities that there is a separation of powers, the Egyptian government itself must ensure that the normal rules of judicial conduct should apply and Mr Halawa should be returned home.
Mr Halawa's sister Nosayba said he has described how waiting to be freed was like seeing heaven but not being able to touch it
The Irish Embassy in Cairo has received authorisation for a consular visit with Mr Halawa and arrangements are now being made.