Lisa Webb, Which? Consumer Law Expert, said: "Aer Lingus' sudden cancellations of flights to and from the UK and Europe will cause thousands of passengers distress and anxiety when it comes to their travel plans. "In events such as these, airlines should be offering the option of a refund or to reroute passengers on any reasonable route as quickly as possible, using other airlines where necessary. "Aer Lingus must also give clear information to affected customers about their entitlement to compensation." ENDS