Arcadia tycoon Sir Philip Green has rounded on online fashion rival Asos over its use of Topshop branding on its website, warning that he will sue the company if it does not stop taking “unfair advantage of our trademark”.

The Daily Telegraph reported that Green sent a legal letter to Asos warning it that unless it took the Topshop brand down from its website he would sue.

Green was angered over Asos enabling customers to sell second-hand clothes from any retailer on its website, including Arcadia’s flagship brand Topshop.

The Arcadia boss has claimed that Asos Marketplace uses Topshop’s brand name too often and too prominently and that the website gives the impression that it sells new Topshop clothing, despite the fact that no such agreement is in place between the retailers.

Green told the Telegraph: “I feel Asos misrepresents our brand, which is registered to us. They claim to sell new Topshop clothes when they don’t. That’s an infringement of our trademark. This is not the first time it has happened.

“They would love to sell Topshop. They’ve had many conversations with us, but I’ve always said we are not interested. We have our own website.”

Asos chief executive Nick Robertson replied by maintaining: “A shopper might well have a new item and then they are selling it straight away. That does happen. This is no different from eBay. We will look at his complaint carefully but to my knowledge I have created a platform which allows people to recycle their wardrobe.”