The room-rental website, now worth $30bn, faces a critical year as city authorities clamp down. In the back room of a pub in Kentish Town, a group of middle-class Londoners are perched on velvet-covered stools, eating hummus and talking about property. On the wall, above a pile of empty beer kegs, a slide presentation is in progress. A video of Airbnb’s recent advert shows smiling hosts opening their front doors and declaring their support for Sadiq Khan’s post-Brexit “London is open” campaign.