Britain's Business Secretary Kwasi Kwarteng said he was concerned by a so called 'pingdemic' in which hundreds of thousands of workers have been told to self-isolate after being alerted by the NHS Covid app as fears grew of food and fuel shortages. "We're very concerned about the situation," Mr Kwarteng said when asked about reports of empty supermarket shelves in some areas. "We're monitoring the situation." Britain's food supply chains are "right on the edge of failing" as absence related to Covid-19 has aggravated a critical shortage of labour, a meat industry body said yesterday. Latest coronavirus stories Mr Kwarteng said a list of critical workers who will be eligible for loosened isolation rules if pinged by the NHS Covid app will be