Dystopian Britain

I was thinking of writing a story about a dystopian version of Britain. Britain in this story is a real superpower with a huge empire up until 2001 (when the story occurs). The government is a monarchy still, with the monarch (a Tudor) being a fascist dictator running the country in a fashion akin to Hitler. Technological development is slower here (steering away from V for Vendetta), looking like the 1920s-1940s, roughly. Surveillance is not entirely omnipresent (steering away from 1984) so the character do get to do meaningful things. Unlike Hitler's Germany, there are no wars going on that threaten the realm - this is a reasonably stable totalitarian monarchy. Any ideas on how to put a British spin on this?

I don't know about viability, but the back-story should be interesting.