With the UK still reeling from more than three years of debates about Brexit, even simple packaging can set off hair triggers, with some fearing any expression of national pride.

In this feverish environment a picture of a Co-Op ice cube bag emblazoned with a British flag and the words “made with British water” has sparked a meltdown on Twitter.

“What is British water exactly? Does it fall on the left, live in a thatched cottage and think itself superior to other races of H2O?” one exasperated commenter asked.

“Water flows here, there and everywhere. Water, like fish, knows no borders. The Co-op has been and should be better than this. Stop it,” another added. “What next? British air?” came another wry response.