The cost of the 32-hour visit to Ireland of Pope Francis is expected to compute at about €1 million an hour.
“This is bigger than the Queen, bigger than Obama,” said one Government official, when asked about the ultimate cost to the State of hosting the pontiff later this month.
Security costs alone for the visit of Queen Elizabeth II and US president Barack Obama soared to €36 million, despite initial projections they would run to about €20 million.
The Catholic Church, through its parishioners and donors mostly, will stump up much of the costs of the first papal visit in almost four decades.
It has committed to raising €20 million towards the 32-hour itinerary, much of which comes under the programme of the World Meeting of Families, an international church-organised festival, hosted in Dublin this year.
There will be significant security costs for a planned Popemobile tour around central Dublin
But the State faces major costs too.
The organisation and policing of a 500,000-ticketed Mass at Phoenix Park, an expected highlight on the Sunday of the visit, is expected to run into millions of euro.
It could take millions more to prepare the park and repair it afterwards.
There will also be significant security costs for a planned Popemobile tour around central Dublin as well as his trip to the basilica at Knock.
Asked last month in the Dáil about the public bill, Taoiseach Leo Varadkar suggested somewhere between €10 million and €20 million. However, he acknowledged this could rise.
The Government is treating it as a major event for the country with a high international profile
“We do not have a cost or budget yet either for the security or for the reinstatement of the [Phoenix] park, but we estimate it will be in the same ballpark as Queen Elizabeth’s visit,” he said.
“In other words, it will probably be more than €10 million and less than €20 million but that is only an estimate at this stage.”
Even if it were at the lower end of the scale, between State and church, the trip looks set to cost at least €1 million an hour.
Although not a formal State visit, the Government is treating it as a major event for the country with a high international profile.
State involvement, and therefore costs, will be the same as would be incurred for an official visit by a head of state, and will include security, public safety, protocol and co-ordination.
All the gates are being removed to improve the flow of pedestrian traffic
As far as the public purse is concerned, the majority of the costs will be borne by the Office of Public Works (OPW).
Last month, it awarded a €1.2 million tender to Mongey Communications to provide temporary CCTV cameras as well as other security and communications technology at locations including the Phoenix Park and Dublin Castle.
Two further tenders, worth €900,000 each, were advertised for security and stewarding services both within and outside the Phoenix Park.
Also, the OPW reportedly sought €924,000 from the State coffers to renovate the Phoenix Park in preparation for the event. All the gates are being removed to improve the flow of pedestrian traffic. The ultimate cost of park repairs will be influenced by the weather conditions.
The Garda costs will be substantial. Some reports put them at €5 million.
Minister for Justice Charlie Flanagan has said a "centralised budget was reserved" by Garda chiefs for security costs related to the Papal visit, so it would not impact on day-to-day policing costs in local districts.
The Health Service Executive (HSE) will also bear huge costs.
One Government official close to the organisation of the event said the health and safety operation was “unprecedented”.
More than 1,000 doctors, nurses and paramedics will be stationed at 1.5 km intervals on all routes to the Papal Cross at Phoenix Park for Sunday’s Mass.