Not exactly... It was in Britain. But apparently the writers didn't feel it necessary to learn anything about Britain, or perhaps even talk to someone from there to learn about the way the country works, their culture, and any of the thousand differences that make one nation different from another. Instead they just did America with an accent.

Let alone changing the ending to have everyone in London dressed as V for some reason. But I'm sure there were other reasons.

That said, I love the propaganda-esque Freedom! Forever! posters. and Alan Moore's favorite movie is Performance so what does he know?