The first thing I notice when I meet Sian Berry is the whiteboard.
Written across it in different colour pen are numbers – various calculations a la A Beautiful Mind. The complicated maths dominating one side of the small office room is an insight into how the former co-leader of the Green Party does politics.
“We were the only ones paying attention when [Sadiq Khan] published his draft budget,” says Berry, who had just spotted that the mayor of London was planning to freeze fares – but hadn’t announced it. “We pay attention to everything the mayor does. We look for gaps, we look for opportunities. We were looking very closely at that number.”
