UK ministers are drawing up emergency contingencies for the food industry after fears that a prolonged disruption to shipping through the Strait of Hormuz could leave supermarkets short of carbon dioxide, a gas used across meat processing, packaging and drinks production. According to The Guardian, officials from No 10, the Treasury and the Ministry of Defence have taken part in a planning exercise, codenamed Exercise Turnstone, to test how British industry might cope if the channel stayed shut into June and a wider settlement in the Middle East failed to materialise.

The concern is not about food alone. Carbon dioxide is used to stun pigs and chickens before slaughter, to extend the shelf life of fresh meat, salad and baked goods, and to produce fizzy drinks and beer. It also has industrial and medical uses, including in refrigeration and hospital procedures. The government has already moved to shore up supplies by committing £100m in March to restart the mothballed Ensus bioethanol plant on Teesside for three months, a step ministers presented as a resilience measure.

Business secretary Peter Kyle sought to calm fears on Thursday, telling Times Radio that contingency planning should reassure the public and insisting that carbon dioxide was not, in his view, an immediate risk to the wider economy. Speaking to Sky News, he said people should carry on normally, adding that the government would be frank if the situation worsened. Tesco chief executive Ken Murphy also said the retailer had seen no disruption in its supply chain and had not been alerted to any problems by suppliers, while backing the government’s decision to prepare for a worst-case scenario.

The warnings come as the Iran war enters its sixth week and pressure builds on global supply chains. FoodNavigator has reported that attention is shifting from oil prices to the cargoes stuck on more than 2,000 ships in the region, with grains and edible oils among the goods at risk. Earlier warnings from industry figures suggested British shoppers could also face higher prices and possible shortages of pork, chicken and some fruit and vegetables if energy and greenhouse costs rise further. For now, supermarkets say they are coping, but ministers appear to be preparing for the possibility that the disruption lasts long enough to show up on shelves.