Primark is accused of infringing design rights over six different items including a zigzag linen skirt, curved panelled skirt, tropical floral print swimwear and girls' corduroy trouser.
Monsoon said it felt it had no choice but to resort to legal action to protect itself following the earlier complaint in May 2004 over items of clothing including a butterfly dress and an item that appeared to be a copy of Monsoon Girl's Brittany top. That legal action resulted in Primark having to pay out a settlement of £23,000.
All of the latest garments in questions have now been removed from the stores, however, and Monsoon said that it was seeking not only damages from Primark, but a commitment from the company that it will not repeat the actions.
Monsoon chief executive Rose Foster said: "Monsoon and Accessorize are strong brands with a distinctive identity of which we are very proud. We take any infringement of our design and copyright very seriously."
Primark is also locked in a similar battle with high street-chain H&M, which claims Primark copied various prints and designs from its range. Primark declined to comment on the case.
The legal move comes as Monsoon confirms it has bought 47 leasehold stores from Etam in a £43m deal with Bhs owner Philip Green, who acquired the 200-outlet chain from French firm Etam Developpement two weeks ago.
Monsoon said it would convert the shops to Monsoon or Accessorize formats boosting its High Street presence.
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