The Irish dairy company behind well-known brands such as Kerrygold has started stockpiling cheddar in the UK to guard against the risk of a major price hike for Britain’s favourite cheese in the event of a no-deal Brexit.

World Trade Organization tariffs on cheddar are as high as 42%, but Irish cheese manufacturers fear sales would plummet in British supermarkets if it passed on the full extra cost to the consumer.

Ornua, formerly called the Irish Dairy Board, which also owns the Pilgrims Choice and Dubliner brands, has confirmed that it is building up stores of cheddar in warehouses in Britain and Ireland to ensure that its product can both get to supermarket shelves and beat any shock price hike if Britain crashes out of the bloc on 29 March.

“As the full implications of Brexit are unclear, Ornua is managing downsides and preparing for uncertainty,” it said in a statement. “As such, Ornua has increased its storage capacity in the UK to facilitate increased storage of Irish cheddar. This is to ensure a consistent and secure supply to meet the needs of Ornua’s strategic customers in the UK market.”

Ireland has benefited from the British appetite for cheese. The damp climate and low population means the country produces far more milk than it can drink. Much of the surplus fills the milk deficit in Britain, with dried milk, ice-cream and cheese among Ireland’s biggest exports.

Of the 200,000 tonnes of cheese made a year in Ireland, 90% is cheddar. Half of that is exported and half of all exports are destined for the UK.

Ornua was set up by the government in 1961 and this year posted record sales of about £2bn after dairy prices recovered.