Thomas Cook pilots will strike on Saturday after five days of talks failed to resolve a dispute over pay.
Members of the British Airline Pilots' Association (Balpa) will walk out for 24 hours, with further industrial action threatened.
The two sides have been meeting at the conciliation service Acas after a dispute flared over a 1.5% pay offer. The union is seeking a rise in line with inflation and better travel facilities.
The pilots staged a 24 hour strike earlier this month.