Of course there isn't a British race. There isn't even an English race. The only people who seriously think nationalities are "races" are racists.

Actually the whole concept of "races" is a pretty daft idea. We don't use the word in relation to any other species do we? People vary genetically around the world, but it just isn't sensible to slice the human race into a few neat subdivisions, we overlap too much. There's probably as much genetic variation among "white" people and "black" people" as there is between them.

And watch it, being rude about Klingons...