The UK government is drawing up contingency plans for potential gaps on supermarket shelves if ongoing disruption caused by the Iran war continues to affect supplies of carbon dioxide. Officials from Downing Street, the Treasury, and the Ministry of Defence have conducted a planning exercise called Exercise Turnstone, run by the Cobra emergency committee, which modelled scenarios including a prolonged closure of the Strait of Hormuz (a critical Persian Gulf shipping lane through which key industrial imports flow) and a mechanical failure at a major British CO2 production facility. CO2 is essential to the food industry for the humane slaughter of livestock, preserving packaged meats and fresh produce, carbonating drinks, and refrigeration — meaning any shortage could affect supplies of chicken, pork, fizzy drinks, and beer ahead of the football World Cup in June. Business Secretary Peter Kyle said the public should be reassured by the government's planning, noting that a £100 million investment to reopen the mothballed Ensus bioethanol plant on Teesside would bolster domestic CO2 resilience; Tesco, the UK's largest retailer, said it had so far seen no supply chain problems related to CO2 availability.