Passengers flying to Greece today face disruption due to planned strike action by air traffic controllers.
The walk-out is due to start at 2pm local time and finishing at 6pm.
British Airways, Easyjet and Ryanair have all rescheduled and cancelled a number of flights due to the four hour strike.
Passengers affected by the action have been told they will be offered free of charge transfer to a new flight or full refund.
In a statement Ryanair said: “We are not yet certain of the level of disruption expected. In the event we are forced to reschedule or cancel flights, we will update this notice accordingly.”
EasyJet said: "We are doing everything possible to minimise the impact to our customers, but unfortunately we will have to cancel some flights.
"Despite this being beyond EasyJet's control, we sincerely apologise for this inconvenience. We are working on alternative plans to attempt to move as many affected customers as possible and we will provide further updates.”
The UK Foreign Office has warned that further strikes were possible on August 14 and 15.
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