In the second-floor room of a building on Tufton Street, Scotland’s former first minister Alex Salmond delivered a press conference this afternoon to London journalists. An untouched tray of biscuits sat on a coffee table at the back, while the rest of the room was rather merch-light thanks to forgetful organisers not transporting more materials from Scotland: a party banner was illuminated on a TV screen and seats were covered in ‘general election briefing’ PDF print-outs.