The family of an Irishman, imprisoned in Egypt for more than three years without trial, have urged the government to do more to help free him.
Ibrahim Halawa, 20, the son of Ireland's most senior Muslim cleric, was arrested during anti-government protests in Cairo in August 2013.
He is due in court on Saturday along with 463 others, charged with inciting violence, rioting and sabotage.
They all face a possible death penalty, if convicted.
Three months ago, Egypt rejected a called from the Irish government for the immediate release of Mr Halawa, whose family live in Dublin, under presidential decree.
The Egyptian government has also rejected allegations by the United Nations about his treatment in prison.
Mr Halawa's trial has been postponed 15 times and his legal team fear another adjournment.
Amnesty International held a vigil at Stormont on Tuesday to show support for a campaign calling for his immediate release.
Those who took part included MLAs from Sinn Féin, the SDLP, Alliance and People Before Profit.
Mr Halawa's sister, Khadija, was there along with her husband and two young children.
She called on the Irish government to do more to put pressure on the Egyptian authorities to release her brother.
Irish Foreign Affairs Minister Charlie Flanagan has said the case is a "key priority" and he met his Egyptian counterpart in Cairo in June to underline the government's concerns.
But the family and their supporters say the Irish government could do more.
"We are very concerned about him, about his treatment in prison, and what might happen to him" said Khadija Halawa.
"The Irish government has tried to do something, but it needs to be doing more and it can do more. It should be more pro-active, and should be taking immediate steps and not just wait for the presidential decree.
"There should be more communication with the Egyptian government to try to have something done."
Amnesty International has declared Mr Halawa a prisoner of conscience.
Patrick Corrigan, Northern Ireland programme director for the human rights group, has supported the family's call.
"This young Irish citizen has spent more than three years living in horrific conditions, without access to proper medical care, and without any prospect of a fair trial," he said.
"Amnesty International remains gravely concerned for his physical and mental wellbeing and we reiterate our call for his immediate and unconditional release."
Mr Halawa was 17 when he was arrested along with three of his sisters after Egyptian security forces ended a siege at the Al-Fath mosque in Cairo in August 2013.
They said they were on holiday at the time and sought refuge in the mosque to escape the violence outside. His sisters were later released on bail.
The family has denied claims that Mr Halawa is a member of the Muslim Brotherhood, Egypt's oldest and largest Islamist organisation.
The Egyptian government has declared it a terrorist group, a claim the organisation rejects.
More than 1,000 people have been killed and 40,000 are believed to have been jailed since President Abdul Fattah al-Sisi led the military's overthrow of Mohammed Morsi, Egypt's first democratically elected head of state, in 2013.