US clothing giant Gap Inc is expected to reveal a 24 per cent drop in worldwide year-on-year sales on Thursday when it releases its December sales figures for its 3,800 stores around the world.

The company, which has 133 shops in Britain, has seen sales decline for 20 consecutive months, with its bonds trading at junk levels and analysts warning it may soon lose its investment-grade credit rating.

A spokeswoman for Gap UK today admitted the company had made design mistakes but was confident it had rectified them in its new spring collection which will hit stores later this month.

Shoppers are promised jeans with leaner legs, well-fitting twill trousers, bomber jackets in denim or khaki twill, trench coats for men and T-shirts with a vintage look.

"We lost focus in the brand," the spokeswoman told the London Evening Standard newspaper on Wednesday. "We were too swept away by trends and lost consistency. We didn't focus on the key items.

"Now our main priority is to get the designs right and keep to the fundamentals like making the stores easy places to shop. "We're confident we will get our momentum back," she added.