The Ryanair group chief executive has issued a stinging rebuke to the Government over its failure to implement the EU Digital Covid Certificate (DCC), saying it is causing untold damage to tourism and the economy.

In an open letter sent to the Minister for Transport, Michael O'Leary sought an explanation from Eamon Ryan as to why Ireland was the only EU member state not ready to comply with the DCC when it came into effect yesterday.

Mr O’Leary said this was despite confirmation from the provider of the system that it can be switched on right away by Ireland for vaccinated citizens.

"This ongoing mismanagement of air transport by the Irish Govt (sic) is doing untold damage to our economy and tourism infrastructure as we lag 'Paddy last’ behind every other EU country, all of whom have opened up to these EU Covid Certs and are taking advantage of the success of their vaccination programmes," Mr O’Leary wrote.

"Instead Ireland continues to be uniquely locked down despite having less than 45 Covid patients in hospital and less than 15 in our ICU’s."

The Government is planning to introduce the DCC from July 19.

The system is to be used to prove that travellers have either been fully vaccinated against Covid-19, received a negative test result or have recovered from the virus and is seen as a key tool in restarting air travel across the EU.

On Wednesday the European Commissioner for Justice said Ireland was not ready to comply with the certificate system when it came into effect on July 1 due to the recent cyberattack on the HSE.

But the Ryanair boss claims this is not the case.

Mr O'Leary said that as a result of the Government's "ineptitude" the airline now has to refuse travel to passengers from all other EU states who are fully vaccinated and in possession of a valid certificate.

"This is discriminatory and unjustified without any medical or public health basis," he added.

He also claimed that Ryanair has received reports of Irish passengers arriving into the state with a certificate who are being "unjustly threatened with mandatory quarantine."

"Please explain why Irish Borderforce today appear to be completely unaware of what the EU Covid Certificate looks like?" the airline boss asked.

"What have you been doing for the last 6 weeks since the DCC was first announced?"

Mr O’Leary also sought confirmation from Mr Ryan that the Covid certificate system will be immediately switched on for all 1.5 million fully vaccinated people here, claiming they pose no threat or risk to the the National Public Health Emergency Team’s (NPHET) "variant scariant lockdown narrative."

Earlier, Dr Cillian de Gascun, the Director of the National Virus Reference Laboratory and member of NPHET expressed a personal view that it would be "too early" to open up travel to other EU member states on July 19.