The Priests will be headline performers at the climax of the 50th International Eucharistic Congress.
Around 80,000 pilgrims are expected to pack Croke Park in Dublin for "Statio Orbis" on Sunday June 17 — the closing ceremony hosted by Liveline presenter Joe Duffy and newscaster Eileen Dunne.
The Priests — Fr David Delargy, Fr Eugene O’Hagan and his brother, Fr Martin, who recently renewed their contract with Sony, expect singing at the closing Mass to be a thrilling but daunting experience.
Fr Eugene said the IEC was coming at a critical time in people’s lives in Ireland.
"The IEC will strengthen our faith, our vision and our commitment to make real what we believe is at the heart of the Eucharist."
The trio have been singing together since they were boarding students at St MacNissi’s College in Co Antrim.
After signing their first record deal with Sony in April 2008, the priests, all from the Diocese of Down and Conor, were allowed record part of their debut album in St Peter’s Basilica in the Vatican.
Also performing at the closing ceremony will be award-winning soprano Celine Byrne who has said her faith meant a lot to her.
"To be invited to participate in the International Eucharist Congress is both an honour and a blessing for which I am grateful."
Ireland’s Three Tenors will perform at the IEC’s opening ceremony at the RDS in Dublin on June 10.
The opening ceremony will be hosted by RTÉ newscaster Bryan Dobson and TG4 presenter Róisín Ní Thomáin and both the opening and closing of the IEC will be broadcast live on RTÉ.
Meanwhile, Cardinal Oscar Rodriguez Maradiaga said compulsory celibacy was not to blame for a shortage of priests.
He said the problem was the life-long commitment to the priesthood — a similar problem could be seen in marriage where many people found it difficult to make a life-long commitment.
The cardinal who is Archbishop of Honduras, was speaking at a media briefing on the opening day of the International Theology Symposium at St Patrick’s College, Maynooth, Co Kildare.
The theme of the three-day event attended by around 400 people is "The Ecclesiology of Communion 50 Years after the Opening of Vatican II" and precedes the IEC opening liturgical ceremony.
Cardinal Maradiaga said both the symposium and IES went to the root of the faith of Roman Catholics.
"We know that the Church lives for the Eucharist and is built up by the Eucharist. So we are talking about a centre-point of our faith," he said.