We have never had a moment like this before in our history: a time when the Prime Minister is, in the most personal way possible, fighting the very problem his government is trying to tackle. After Boris Johnson tested positive for coronavirus, he insisted that he would keep leading the government from self-isolation in Downing Street. His determination was influenced by the fact that No. 10 believed that parts of government needed pushing to make sure they delivered; there is frustration in Downing Street about the speed of progress in testing, for instance. But those in virtual meetings with him did worry that he was often coughing, and his performance was not up to his usual standard. When he was admitted to hospital on Sunday, some thought this would allow him to get some rest.