Health experts dismiss O'Leary claims it is safe to fly again

They have also warned that quarantine for arrivals into the country should be “mandatory, rigorously enforced, and observed”. Mr O’Leary has repeatedly called for quarantine plans to be abandoned.

Mr O’Leary said it “makes little sense for Ireland to be locking down further” when other countries are opening up. Ireland should remove its ineffective and unnecessary travel quarantine from the EU, he said.

He said the airline was following the advice of the European Centre for Disease Control which emphasised the importance of face masks and hand sanitiser, but said quarantining passengers was a matter for individual governments.

Gabriel Scally, president of public health at the Royal Society of Medicine, said he does not know where the Ryanair chief has received his information.

Speaking on RTÉ radio’s Today programme, Dr Scally said Ireland is in a good position with the number of Covid-19 cases reducing and that “the last thing you need to do is to start bringing cases in from elsewhere”.

Dr Scally said people should not take public health advice from Mr O’Leary. Masks would help, but even with fewer passengers there is still a risk of spreading the virus, he said.

Dr Scally said quarantine for those arriving into Ireland from overseas should be mandatory, rigorously enforced, and observed. Mr O’Leary earlier described the quarantine as “simply political game playing”.

Kingston Mills, professor of immunology at Trinity College, warned it is important not to import cases into Ireland from countries “not doing well”.

“If we get the numbers down, the best way to keep it down is not to import any cases,” he said.

Mr O’Leary also told RTÉ it will take between three and six months for all customers to receive their refunds for cancelled flights. He said €400m has already been refunded, accounting for one third of the total owed to customers.