Covid quarantine rules forced Ryanair to fly an empty jet from Paris to Dublin last week, the group revealed as it called for the restrictions to be axed.
The Government requires passengers from countries including Austria, Belgium, France and Italy, to quarantine in hotels for two weeks, a rule that has sparked criticism from the EU.
Ryanair called on Taoiseach Micheál Martin on Friday to scrap the controversial travel curb and initiate plans to reopen the Republic on time for summer holidays.
Eddie Wilson, chief executive of the group's biggest airline, Ryanair DAC, revealed that the rule forced the carrier to fly an empty aircraft from Paris to Dublin last week. He explained that the "few passengers" who turned up for the flight could not fly as they had not booked quarantine hotels.
“This was at the same time that the Minister for Health was criticising airlines for not doing their job,” Mr Wilson added. “We’re not only doing our job, we’re being criticised for it.”
He warned that if the Government did not begin planning to reopen for travel within Europe, Ryanair and other airlines would simply move aircraft from the Republic to other countries. This would cut the State's links with the rest of the EU, as there will be a limited number of aircraft flying in the region as the Covid crisis recedes.
“That capacity will just slip away,” Mr Wilson predicted. “There will be at least a 30 per cent reduction in intra-European capacity as we come out of this.
"We have just opened a base in Zagreb, our first one there, as they are aware that there will be less capacity."
Mr Wilson said that Ryanair was also in talks with Sicily, Paris Beauvais Airport and others across Europe that were anxious to secure aircraft to prepare for travel's reopening .
He pointed out that Ryanair and its rival carriers were allocating aircraft to routes now for later in the year and the winter season. The airline boss argued that the hotel quarantine rule was pointless as travellers could avoid the measure by coming into the Republic via Belfast, Britain or from EU countries not covered by the restriction.
“There are 22 other nations that you can fly from, or you can come through the UK,” he said.
He noted that while the Republic’s vaccine programme was beginning to lag Europe’s, the EU was planning for measures including vaccination passports from June on the basis of an improving public health situation.
“We have gone the exact opposite route, excluding the Austrians, French, Belgians and Italians because they have got some sort of public health programme while we are whiter than white,” Mr Wilson said.
Ryanair earlier called on the Taoiseach to scrap the hotel quarantine rule for EU travellers, calling it “absurd” and “pointless”.
The carrier, Europe’s biggest, pointed out that vaccinating the Republic’s most vulnerable groups had cut hospitalisations and serious illness, with fewer than 50 cases now in intensive care. It argued that the Government should set clear times for the reopening to travel with the EU before the end of May to ensure that all citizens who have been vaccinated can move without restrictions.
The airline warned that the Republic could not continue to be Europe’s failed outlier.
Ryanair's call followed a similar plea from the National Civil Aviation Development Forum to axe hotel quarantine and set targets for reopening to travel.