Flights to Spain could be affected by industrial action being held by airport ground staff.
Three Spanish unions have announced strikes by baggage handlers on four days in September which will affect airports in Madrid, Barcelona, Alicante, Malaga and Majorca.
Stoppages by workers are scheduled to take place during peak morning and evening periods on September 4, 11, 18 and 25.
The Workers Commission Union, one of the unions taking industrial action, said that Easyjet and Vueling are likely to be most affected by the strikes.
The three unions have blamed handling firm Menzies Aviation Iberica for the strikes. The unions said that the company had postponed a collective bargaining agreement.
Easyjet said in a statement to passengers: "Like other airlines flying to and from Spain, we expect an impact to our flights.
"We would like to assure you that we are preparing for any disruption if the strike does proceed and will do everything possible to limit the inconvenience of this on your journey."