Powerful property and farming firm Grosvenor Group says knock-on effect of Iran war could arrive next year

Fertiliser shortages caused by the Iran war have driven up costs for UK farmers by up to 70% and will have a “dramatic” impact on food prices globally next year, according to one of Britain’s most powerful property and farming companies.

Mark Preston, executive trustee of the 349-year-old Grosvenor Group, controlled by the Duke of Westminster, said fertiliser “was already quite expensive” before the 50% to 70% surge in prices since the start of the Iran war in late February.

The effective closure of the strait of Hormuz – which Iran’s Islamic Revolutionary Guard Corps said on Wednesday could soon reopen – has throttled global supplies of fertiliser, crucial to growing food crops.

Preston said that, although UK crops were unlikely to be affected this year as most fertiliser had already been used, the knock-on effect could arrive next year. “Farmers are not buying that fertiliser, they’re sitting on their hands and hoping things will improve, which they probably won’t,” he said.