The actors in this movie are all native speakers of the English language and speak the language with great clarity. Unfortunately, it is a language which has not been spoken in America for at least a century. I come from the opposite side of the world from England, but don't tend to have any problem with their films and television. You should be grateful that the DVDs have English subtitles. When it comes to American DVDs, they often fail to provide the sorely-needed English (or even American) subtitles, opting instead for Spanish and/or Portuguese!
Unfortunately, you're correct. There are a lot of fascinating things about american English(mid-20th century slang) but it's a drag that it takes a touch of effort for us over here to understand you all at points.
You're obviously full of it. One can only make educated guesses at some of Nosher Powell's utterances and there are other passages in this movie that are difficult to understand. I think the problem has little to do with language differences in the UK and US although there were some terms used that are unfamiliar to most Americans. Eat the Rich is certainly not alone here and I think unintelligible dialogue in films and TV has gotten far worse since this film was made.
Actually, the British accent was something the British upperclass made-up to distinguish themselves from the lower class. Everyone copied it. It is NOT the original English accent, though.
I'm not a native speaker but I didn't have any problems with this movie, so I wonder why anybody (especially somebody whose mother-tongue is some kind of English) would need English subtitles...
'Cause the Britons invented their fake British accent (literally, read up on its history), then corrupted it so much (cockney) that people who speak non-accented English (americans) can't understand it. Different words, to not pronouncing the letter "h", different cadence, different slang. I've had to use subtitles a lot during Trainspotting and A Clockwork Orange.
"people who speak non-accented English (americans)" Non-accented?!? Get your head out of your ethnocentric behind. Again, one of my fellow countrymen has embarrassed me.