I know, but what happened to Advertising Standards? Aren't they supposed to be "legal, decent, honest and truthful"? Note the distiction between "honest" and "truthful", indicating that it's not enough for a claim to be true, it must also be honest - a fine but important distinction that means that advertising must not allow truth to mislead.
http://news.bbc.co.uk/2/low/programmes/working_lunch/4588635.stm
The problem with advertising standards is the limitation of coverage, they can action against misleading advertising in magazines and newspapers, but I am informed that iof the information appears in a companies website they have no jurisdiction, so therefore you can make any claims you like on a website and they apparently cannot touch you for it!!