Could be put in place if necessary. Our correspondent Angus Crawford reports. Empty streets, empty parks. What a difference seven days can make. Last sunday, social distancing meant little to some then came the lockdown, an urgent attempt to stop the spread and protect the nhs. Despite that, more than 17,000 people have tested positive, including borisjohnson, now chairing cabinet meetings from self isolation. Hes also writing a letter to 30 million homes across the uk, in which he says. I cant make an accurate prediction but everyone does have to prepare for a significant period when these measures are still in place, and the response so far from the british people has been fantastic, as i say. I wish i could predict when this will end. But its vitally important that, at the moment, and four weeks ahead, people maintain the strict social distancing guidelines that have been laid out. The new nhs nightingale taking shape in east london. A makeshift command centre created in less then 2