"Fashion has always been political since the days when sumptuary laws prohibited people of lower rank from wearing certain fabrics," says Caroline Evans, professor of fashion history at Central Saint Martins College of Art and Design.
"But there are new, unwritten laws as to what kind of clothes political figures choose to wear. Like it or not, in a media age they will be judged by their appearance as much as by their convictions."
But politicians need to play the game carefully, insists Simon Doonan, creative director of Barneys. "Image is vital, but people need to feel gravitas from their politicians - and you don't feel gravitas from a politician who's wearing Dolce & Gabbana."