The combination of Covid-19 and Brexit is a double whammy. The first was a haymaker that hit Britain from nowhere. The follow up will come when Britain, quite deliberately and with malice aforethought, winds up its fist and punches itself in the face. The economic impact of the virus will be accentuated by the UK leaving the EU without a deal or with a meagre free-trade agreement, warns a grim report, sponsored by the Best for Britain think tank.