Supermarket supply chains are "starting to fail" because the "pingdemic" is sending thousands of workers into self-isolation, food industry leaders warned on Wednesday night. Shop shelves in some areas were empty of basic supplies, while petrol stations ran out of fuel as the NHS Test and Trace app threatened to bring parts of the economy to a standstill. MPs and industry leaders urged the Government to ease the growing crisis by including supermarket staff, lorry drivers and other frontline workers on a list of those exempted from automatic self-isolation when 'pinged' by the app as a contact of someone with...