Best of British luck

Posted by Mark Sevier on May 14, 2010 at 07:31

"Best of British luck" seems originally to have been a sarcastic way of implying heavy doubt of success. For example, "You're going to swim that crocodile-infested river? Well, best of British luck!"

However, in recent times I hear it used almost consistently as a sincere wish for good fortune. Can anyone help me with explanation or origin?