The producer confirmed that it had take legal action “in relation to an intellectual property matter”.
A Diageo statement said: “It would be inappropriate for us to comment further other than to say that Sainsbury’s is a valued customer of Diageo and we hope will continue to be so for many years.
“It is Diageo’s firm intent that our strong trading relationship should not be affected by this discrete dispute.”
Sainsbury’s said it intended to “vigorously” defend the action against Pitcher’s, which is labelled as “synonymous with summer” and which carries a serving suggestion with lemonade and fruit.
A Sainsbury’s statement said: “Our customers are savvy enough to know exactly what they’re buying. The clue is in the name, and we see no basis for such an allegation.”