Ryanair has announced plans to restore 40 per cent of its flights from July 1, subject to travel restrictions being lifted with the EU.
However the Government’s announcement on Wednesday is expected to severely impact demand from foreign tourists wanting to come to the UK if they have to self-isolate for 14 days upon arrival.
Speaking on the Peston show, Mr O’Leary said: “Regrettably, Robert, it's been one shambles after another, of mismanagement, making it up as they go along, and the latest of which has been today's frankly shambolic announcement of an ineffective and useless quarantine.
“People now have to fill in a form which the UK government hasn't even published yet."
Mr O’Leary criticised the Government’s announcement of new quarantine measures, saying: “The problem with this quarantine is, it's not a quarantine. You know a quarantine is only effective if you kind of trap people or gather people at the point of entry.
“Here, they're asking people to fill in a nonexistent form on arrival at Heathrow or Gatwick, then get on to London Underground or the trains, buses, public transport, stop off in Tesco, maybe go to Halfords before you reach your quarantine address.”
He said passengers arriving in the UK could easily mislead authorities by claiming they are self-isolating when in reality they are out in society.
He added: “You give them your mobile phone number and in the unlikely event that anybody calls you over the next two weeks, you can answer the phone from a beach, from a golf course, from your office, from your local demonstration outside the Houses of Parliament and say, 'Yes I'm quarantining away in perfect compliance.'"
Mr O’Leary said his company were working on providing refunds to customers, but the crisis had led to his company having to deal with an average of 10,000 refunds a month to 35 million during the last three months.
He said: “At the moment we're about 40 per cent of the way through that backlog, we've about 60 per cent to go, we expect now to eliminate all of those remaining refunds for the months of April, May and June, probably in the next eight to ten weeks."
He also said once flights resume, all passengers will be required to wear a face mask on Ryanair flights.