Is Mike Ashley's biggest failure the rise of JD Sports?

Mike Ashley, the founder of Sports Direct and owner of Newcastle United, said in 2011: "I'll finish off JJB first, then I'll move on to JD."

Mr Ashley succeeded with the first of these ambitions, with JJB collapsing into administration a year later.

However, JD, Sports Direct's last remaining UK rival in the sports retail world, appears to be going from strength to strength.

The retailer has reported a near tripling of pre-tax profits over the last six months. Sales in the 26 weeks to August 2 grew by 27pc to £721m, while pre-tax profits rose 170pc to £16.4m.

While Sports Direct has focused on replica kits and discount sportswear, JD is attracting shoppers by focusing on the more fashionable end of the market, particularly trainers.

The company said that like-for-like sales in its sports stores grew by 13pc across Europe, while sales in its troublesome outdoor arm - which includes Blacks and Millets - also turning around and now growing by 12pc.

Peter Cowgill, executive chairman, said: "The group has delivered record results for the first half with encouraging progress in the principal areas of the business, notably our UK and European sports fascias.

"Our sports operations continue to provide the engine for profit growth and cash generation in the group and will therefore continue to be the primary focus of investment."

Freddie George, analyst at Cantor Fitzgerald, said: "The JD format which has been strengthened over the last two years is clearly differentiated, and has significant potential to be developed overseas with the support of the international sports brands."

Greg Bromley, consultant at Conlumino, added: "The major issue going forward will be to manage an ever expanding empire that contains three different arms - sports, clothing and outdoors - and an ever widening portfolio of fascias.

"Add to this fairly rapid scale international expansion, and you have a business that has the potential to make significant market share gains in its respective markets."