Red faced bosses at Marks & Spencer have admitted to an embarrassing gaffe which led to millions of pairs of knickers being over-produced.

More than 20 million pairs of knickers are sold each year by the company, which is Britain's biggest seller of ladies' underwear. It would normally have six weeks' supplies in stock at any one time, but a mix-up left Marks & Spencer literally sitting on 20 weeks' supplies - more than five million extra pairs of briefs.

"There was a misunderstanding with our suppliers resulting in a backlog," said a spokeswoman for the company. "We did have several weeks' extra supplies, but the problem has now been sorted out and we are back to normal. We got back to normal fairly quickly, in fact, because we sell so many pairs of knickers - as many as 60 pairs every minute," she said.

The company is now trying to reduce stock levels even further. The spokeswoman said that Marks & Spencer was in talks with suppliers to try to reduce lead times from six weeks to four weeks, while still maintaining quality.

"Underwear is now far more susceptible to fashion trends. Those trends are changing all the time and we want to be able to react to trends more quickly. Reducing lead times will help us to do that."

By Clive Hinchliffe.