Ask Cara, Poppy, and Chloe Delevingne. The Celebrity sisters are the co-founders of vegan prosecco brand Della Vite. Unfortunately for them, the advertising campaign they’ve devised has triggered a furious response from the Comité de Champagne. The Comité is the official representative of the Champagne producers' interests, and more precisely the use of the appellation Champagne. For them, it’s simple: if you are not an official producer of champagne, you just cannot use the