Waitrose is to ban the sale of high-caffeine energy drinks to children aged under 16.
The supermarket said customers buying drinks containing more than 150mg of caffeine per litre would be asked to prove their age from 5 March.
The move follows concerns over the impact of the high sugar and caffeine content on children.
Teachers’ union NASUWT said one in 10 teachers cited energy drinks as a key cause of poor pupil behaviour.
Waitrose said its decision was based on existing industry labelling guidelines, requiring any soft drink with more than 150mg of caffeine per litre to carry a high-caffeine content warning and state it is not recommended for children.
Waitrose director of technical and corporate social responsibility Simon Moore said: “As a responsible retailer we want to sell these products in line with the labelling guidance.
“These drinks carry advice stating that they are not recommended for children, so we’re choosing to proactively act on that guidance, particularly given the widespread concerns which have been raised about these drinks when consumed by under 16s.”