The BSI logo

"If the weave is open of the item of clothing, more ultraviolet radiation from the sun will get through. That's fairly obvious.

"But once you've got a reasonably tight weave, then other items like the weight like the colour become important."

David Lazenby of the BSI which produced the new labelling system, said: "The clothes that will carry this label will have been tested in approved testing laboratories throughout Europe and there's no question that will be an assurance they do what they say they'll do."

Manufacturers will not have to display the logo, but it is believed many will do so, to reassure consumers their clothes are safe as well as stylish.