A Canadian man has filed a lawsuit against Sunwing Airlines for promising a champagne service and instead serving sparkling wine.
Daniel Macduff booked a holiday to Cuba through Sunwing that advertised a complimentary on-board champagne toast.
Mr Macduff, from Quebec, said he received a cheaper bubbly instead - and only on the outgoing flight.
The airline said it believes the lawsuit "to be frivolous and without merit".
Mr Macduff's lawyer says the class action hinges on misleading marketing and not the quality of the wine served.
"It's not about the pettiness of champagne versus sparkling wine," said Montreal-based lawyer Sébastien Paquette.
"It's the consumer message behind it."
Mr Paquette said references to real champagne - a sparkling wine variety made specifically in the Champagne region in France - was front and centre in Sunwing's marketing materials.
In an emailed statement, Sunwing said the terms "champagne vacations" and "champagne service" were used "to denote a level of service in reference to the entire hospitality package" and not to describe the in-flight beverages.
The airline says it still offers sparkling wine to all its passengers on flights to southern vacation destinations, but are no longer referencing "champagne service" in active marketing campaigns.
Online information now clarifies that passengers receive sparkling wine.
The class action has yet to be certified by the courts, but seeks compensation for the monetary difference between the actual wine served and a glass of champagne as well as punitive damages.
Mr Paquette said about 1,600 other plaintiffs have come forward in Quebec to join the lawsuit.