Regional carrier Flybmi reportedly faces the threat of a strike by pilots in a dispute over pay and conditions.
Pilots in the Balpa union have been balloted over industrial action, according to The Sunday Times.
Balpa said a ballot over strike action was due to close on September 10.
General secretary Brian Strutton said: “It is our belief that this matter can be resolved through negotiation and we remain ready to talk with the company at any time.”
Flybmi said: “The pilots and company are currently in discussions, and we are confident that a mutually acceptable outcome will be reached.”
The threatened strike follows a wave of industrial action in the aviation sector.
Ryanair was forced to cancel hundreds of flights over the summer because of strikes but has announced union agreements with pilots in Italy and cabin crew in Ireland.
Flybmi operates more than 400 flights a week across 11 European countries. It has a fleet of 20 Embraer regional jets and employs more than 400 staff.
The airline is part of holding company called Airline Investments Limited (AIL) group which also includes Loganair.
More: Ryanair agrees deal to end Irish pilot strikes