 Three of Britains leading supermarkets today urged people not to panic buy after images of empty shelves in some areas of the country sparked a rush for the shops. Tesco PLC LON;TSCO, Sainsburys LON:SBRY and Lidl said they were responding to complaints from customers over shortages of certain products and blamed the HGV driver shortage and NHS Covid-19 tracing system that is keeping hundreds of thousands of staff off work. 