Copycat branding in grocery is a growing problem and retailers are even mimicking each other's own label products, it has been claimed.

A survey of 100 brand managers found 60% believed plagiarism of their brands by competitors was a ­bigger problem today than five years ago. Andy Knowles, CEO of packaging design agency Jones Knowles Ritchie, which commissioned the research, said: "We have always seen brands aping other brand's ideas. But we are seeing retailers actually copying own label and the supermarkets starting to plagiarise each other."

A third of suppliers quizzed considered their retail ­partners to be their biggest competitors.