Britain is the “most exposed” nation to jet fuel shortages caused by the Iran war, Goldman Sachs has warned, raising fears of more cancelled flights and ruined summer holidays . The UK is highly reliant on imports that come through the closed Strait of Hormuz and has “critically low levels” of supplies and poor refining tools, analysts at one of the world’s largest investment banks said. Last week, the government asked the four remaining jet fuel refineries in the UK – Fawley in Hampshire, owned by ExxonMobil, Humber in Lincolnshire, owned by Phillips 66, Valero’s Pembroke refinery in Wales, and Essar’s Stanlow site in Cheshire – to do everything they could to maximise supply. Airlines, in turn, have asked the government to relax environmental and noise rules to help them cope with higher costs while the Iran war continues.…