Aldi has become the first supermarket in the UK to effectively ration the sale of all lines as customers continue to stockpile in the face of the coronavirus outbreak.

In a letter written to all suppliers and signed by chief executive Giles Hurley, Aldi said “demand in certain categories remains very high” and added that it is “currently limiting customers to four items of each SKU per visit”.

The letter, dated March 16, said Hurley had also written to customers to “reassure them that Aldi has good availability of products, but that we face challenges in restocking shelves quickly due to such high levels of demand”.

Aldi also followed the lead of a number of other supermarket chains, calling on customers to “consider those who are vulnerable at this time” and reminding them that “not everyone has the financial or practical resources to buy in bulk”.

In the letter, Hurley thanked suppliers. He said: “I appreciate the huge efforts all our suppliers are making to ensure the continued availability of products and services.”

While the discounter is the first to ration across all of its lines, the majority of UK supermarket chains have had to put in place limits on certain products over the last two weeks in the face of stockpiling behaviour from customers.

Tesco was the first to begin rationing certain products, including dried pasta and canned vegetables, two weeks ago. Nearly all supermarkets have since been rationing sales of items such as toilet paper, hand sanitiser and household cleaning products.