Daniel Macduff flew from Quebec to Cuba with Sunwing Airlines, who advertised a complimentary on-board champagne toast. However, a cheaper wine was offered.

Now as many as 1,600 other plaintiffs have come forward to join Mr Macduff’s lawsuit in a possible class action against the airline, which itself claims that Mr Macduff’s lawsuit is “frivolous and without merit”.

Montreal lawyer Sébastien Paquette said: “It’s not about the pettiness of champagne versus sparkling wine. It’s the consumer message behind it.”

He said references to real champagne were front and centre in marketing materials - whereas Sunwing says its use of terms like “champagne vacations” referred to a “level of service”, not in-flight beverages.

It has now amended its website to clarify that sparkling wine is on offer.