All fights between Britain and Europe could be cut off in March 2019 if 'clueless' Government ministers fail to strike a Brexit deal, Ryanair chief Michael O'Leary has warned.
The controversial airline boss said a 'cliff edge' Brexit could close down flights in and out of UK airports overnight.
Prime Minister Theresa May has talked up the prospect of a transition or implementation phase after the end of the official two year period of talks to quit the EU which could resolve the situation.
But some in Europe are reluctant to even begin talks on the future arrangements until the divorce is finalised and Mrs May has insisted no deal is better than a bad deal.
Ryanair chief Michael O'Leary has warned all fights between Britain and Europe could be cut off in March 2019 if 'clueless' Government ministers fail to strike a Brexit deal
Mr O'Leary warned the current 'open skies' arrangement hinges on recognising the jurisdiction of the European Court of Justice which Mrs May has vowed Britain will escape.
Open skies allows flights to travel to and from any point in the EU and the United States.
Mr O'Leary believes it will take more than the two-year time frame from triggering Article 50 to put the necessary agreements in place with the EU.
He said: 'In the airline industry we could be heading for a very difficult divorce with Europe.
'There is a possibility, unlikely, but nevertheless a possibility that there may be no flights between the UK and Europe in March 2019 if the UK walks off this cliff that they seem determined to walk off.'
The airline head said he was switching growth plans away from the UK and would not create any more pilot or cabin crew posts, or increase the amount of planes there due to Brexit uncertainty.
He said new routes announced in Scotland on Thursday would use planes based elsewhere in Europe and would move to other European countries in the event of a hard Brexit.
Mr O'Leary accused the UK Government of being clueless over Brexit and hoped that the UK would stay in the EU.
Ryanair has planes on mainland airport, including at Eindhoven pictured, allowing it to continue flying routes within Europe even if Britain falls out of the 'open skies' system
He said: 'Brexit - no exit plan by the UK Government. I don't think they have a clue what they are engaged in.
'I've had a number of meetings in London in recent weeks where they are going to do a great deal for Britain, and then I got to Frankfurt and Brussels and Paris where they are determined to do Britain down, and I fear they will.
'We have to recognise the will of the the people, they did vote in a referendum, however they were fundamentally misled into believing they could leave Europe and nothing would change.
'Everything is going to change, and probably for the worse.'
Prime Minister Theresa May wants to secure a deal with the EU within the two year official talks period and has talked up the prospect of a transition or implementation phase