BBC News By Sam Francis image copyrightGetty Images image captionSian Berry said she "developed a conscience" while working as a medical writer for a pharmaceutical company Sian Berry joined the Green Party 20 years ago after "developing a conscience" while working for a pharmaceutical company. Ms Berry, who is making her third attempt to become mayor of London, explains how she wants to run the capital from "the bottom up" after being "the average Londoner" for most of her adult life. "I've always worked," Ms Berry said. "I've worked since I was 14 because I needed to." Now 46 years old, Ms ...