Tesco has become the latest grocer to ration eggs due to supply issues. Customers are now limited to buying three boxes of eggs at the checkout because of the dual blows to poultry farmers of rising costs and an avian flu outbreak. Tesco, Britain’s biggest supermarket chain, follows Asda and Lidl in setting limits after they restricted purchases last week. At the time, the retailer said it had “good availability” with no limits – but now a temporary rationing policy has been brought in. It said it is working hard with its suppliers to ensure a good supply of eggs, but has taken the step as a precautionary measure. Farmers have been hit by soaring energy costs in recent months, and the price of wheat has risen because of the war in Ukraine – the grain is a key component in chicken feed. They have also warned about the lack of money they get from supermarkets for the sale of eggs. At the same time, Britain’s largest-ever avian flu outbreak has led the government to tell farmers to keep all poultry and captive birds indoors. There have been 252 cases of the virus since the outbreak began in October last year, with 118 of them coming since 1 October this year alone. Millions of birds have died or been culled in the last year. The government announced on Monday that a bird flu outbreak had been found at a farm near Barnard Castle, Durham. All birds at the site will be culled, and a 3km protection zone and 10km surveillance zone have been set up. After some supermarket restrictions were announced last week, the director of food and sustainability at the British Retail Consortium (BRC), Andrew Opie, said: “While avian flu has disrupted the supply of some egg ranges, retailers are experts at managing supply chains and are working hard to minimise impact on customers. “Some stores have introduced temporary limits on the number of boxes customers can buy to ensure availability for everyone.”