Chanel has said it will leave a historic perfume site in France if plans for a high-speed train line affecting its jasmine fields go ahead.
French rail operators say modernisation work on the French Riviera network is desperately necessary.
But in an open letter, the luxury brand said it would be a disaster for its "artisanal activities" in Grasse.
The company says it takes about 1,000 jasmine flowers to make a 30ml bottle of its famous No 5 perfume.Image copyright AFP
The iconic perfume was created by Coco Chanel when she met local perfumer Ernest Beaux in Grasse during a summer holiday on the Cote d'Azur in 1920.
Part of Chanel's perfume production has been located in the region for decades and the town near the Cote d'Azure is often considered the world capital of perfume.
But French state-owned railway company SNCF has said its whole network in the region is in dire need of investment and wants to route a TGV line through the area.
According to the rail operator, the route from Marseilles to Nice is the most congested in the country outside of Paris.
The 6.7bn euro ($7bn; £5.5bn) investment is expected to cut an entire hour off the trip between the two towns.
But Chanel said "the construction of a viaduct and the regular passage of high-speed trains over these fields of flowers" would force the company "to cease supporting its artisanal activities in the region".
The firm describes the quality of the flowers in the region as "unique and exceptional" and "indispensable for the creation of Chanel perfumes."