Marks & Spencer has agreed a settlement with British sweet-maker Swizzels after accusing it of copying its much-loved Percy Pigs.

M&S said it had reached an “amicable resolution” with Swizzels, who had agreed to change the design of its Pigs Mugs treats.

M&S lawyers had claimed that the sweets were so alike that customers might have ended up buying the wrong ones.

A 37-page document filed at the High Court in London in November said the Percy Pig brand had generated a £131.7 million turnover since its launch in 1993 and currently 271 bags were sold a minute.

M&S has made a significant investment in building a strong Percy Pig brand over the past 30 years and believe it is important to protect the registered trademarks relating to Percy Pig's appearance

In their legal submission, an example was used of a customer who loved the sweets so much they had a tattoo of Percy’s face.

An M&S spokesman said: “M&S has a proud history as a leading innovator and for almost 140 years customers have turned to M&S for unique, original, quality products – conceived, created and developed alongside trusted suppliers and produced to the highest standards.

“M&S has made a significant investment in building a strong Percy Pig brand over the past 30 years and believe it is important to protect the registered trademarks relating to Percy Pig’s appearance.”

Founded in 1928, Derbyshire-based Swizzels is well-known for classics such as Refreshers, Parma Violets and Drumsticks and has been selling its Pigs Mugs sweets since 1996.

M&S has previously taken well-publicised legal action against retailers for infringing their trademarks, but in this case they have taken action against a manufacturer.

Earlier this year, Aldi lost a court battle against Marks & Spencer after being accused of copying its light-up Christmas gin bottles.

The High Court ruled that Aldi infringed the design of its rival’s product, in a major blow to the German discounter, which had denied the accusations.

The case was the latest legal wrangle between the companies, after M&S had previously accused the discount supermarket chain of copying the design of its Colin the Caterpillar cake.

The firms reached a settlement over the dispute last year.