The UK government is drawing up contingency plans for possible gaps on supermarket shelves this summer if disruption linked to the war involving Iran continues to squeeze carbon dioxide supplies.

Officials have been modelling a “reasonable worst-case scenario” in which the Strait of Hormuz remains shut into June, creating knock-on risks for food manufacturing and grocery supply chains.

The concern for grocers is that CO2 plays a critical role across the food system.

It is used in the humane slaughter of pigs and chickens, in the packaging of fresh meat, produce and bakery lines to extend shelf life, and in fizzy drinks, beer and refrigeration. Any sustained disruption would therefore stretch well beyond a single category and could affect availability across parts of the store.

According to reports, ministers and officials from No 10, the Treasury and the Ministry of Defence have taken part in a planning exercise known as Exercise Turnstone, looking at multiple pressure points at once, including continued shipping disruption and a failure at one of the UK’s key CO2 plants.

The government has stressed that such scenarios are planning tools rather than predictions.

Business secretary Peter Kyle has sought to calm fears, saying CO2 supply is “not a concern” at present and arguing that shoppers should be reassured ministers are planning for potential fallout.

The government has also moved to strengthen domestic resilience, backing the temporary reopening of the Ensus bioethanol plant on Teesside after warning that the conflict could threaten gas supplies used by food producers.

Tesco has also pushed back on suggestions that disruption is already feeding through into supermarket supply chains. Chief executive Ken Murphy said the retailer had seen no current problems with CO2 availability and that no suppliers had flagged issues so far, although he said the government was right to prepare for a worst-case scenario.

Earlier this month, the Food and Drink Federation warned that UK food inflation could climb towards 10 per cent by the end of 2026 if the conflict continues to keep pressure on oil, gas and fertiliser markets.

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