The British do not care for an American accent, as much as Americans love an English accent.
Yeah, I think the trend goes in waves- just as American TV goes in and out of fashion over here.
Note that English and British are NOT interchangeable! England, is one of several countries that make up Great Britain. Scotland, Wales and Northern Ireland are also separate countries. Anyone who lives in British Commonwealth countries can hold a British passport, Canada, Bermuda, Australia, India...
You will also need to get a work permit, which while not impossible, you'd have to line up behind citizens of countries in the EEC, who have priority..
I can only think of two 'American' DJs who have made an impression on the British scene; David (Kid) Jensen, a Danish-Canadian! and Emperor Rosko.. (it was his book that sparked my interest in radio!).
I can add a couple more to that, although it's still not a long list...
Charlie Wolf, who began on 80s pop pirate Laser 558 and early 90s 'border blaster' Atlantic 252. Now does talk radio, and a regular on BBC discussion programmes http://en.wikipedia.org/wiki/Charlie_wolf
Paul Gambaccini- New Yorker who has appeared on stations as diverse as Radio One (pop music) and Radio 3 (deadly serious classical station)http://en.wikipedia.org/wiki/Paul_Gambaccini
It would be tough to break straight into London stations- what format do you work on, OP?