ince it emerged that vacuum-cleaner émigré James Dyson was texting Boris Johnson last year to clarify that there would be no change to the tax paid by his workers, in the UK temporarily to build medical ventilators, the issue of political “lobbying” has once again come to the fore. But why is it called that? A “lobby”, from the Latin lobium, was originally a cloister of the sort found in monasteries, not much frequented by the present prime minister. After its introduction in the 16th century it began also to be used to describe any kind of corridor or anteroom. As Polonius says of Prince Hamlet: “You know sometimes he walks four hours together / Here in the lobby.” The political sense is first given in 1640, describing the public entrance hall of parliament: “The outward Room of the Commons House, called the Lobby.” This was designed to enable interviews between MPs and non-members. So when people ask legislators to change the law in their favour, they are “lobbyists”, first recorded in the mid-19th century (along with “lobbying”) for petitioners of the US Congress. Happily, modern technology means you don’t have to stand in an actual lobby to be a lobbyist, but can do it all over WhatsApp.