It always made sense to me that they would use French accents or at least European.
The accents in the last 3rd national US tour of the original staging were so distracting. It seemed as if everyone was intentionally instructed to use American accents right down to the Thenardiers which sounded so bizarre when they started singing "Master of the House" instead of "Master of the 'Ouse"
The rule of cinema is that British dialects are the standard go-to for all of Europe, unless the characters are Nazis or the movie is in a foreign language anyway.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."
Can someone explain the phenomenon Kad described? This discussion came up with a friend when I was watching a movie (filmed in English) that took place in Russia. Most of the actors spoke in some derivation of an English accent. It wasn't remotely close to a Russian accent. I don't understand why this is the default decision for any English language film that doesn't take place in the United States.
Scratch and claw for every day you're worth!
Make them drag you screaming from life, keep dreaming
You'll live forever here on earth.
I don't get why people expect accents. It's already hard to believe the people in Les Miserables would be speaking English so if most of the cast is English they should do an English accent.
There would be no reason for French dialects. The movie will be in English. One doesn't go to see The Three Sisters with an American, British or Australian cast and expect to see it performed in a Russian dialect. Unless one is in Italy, one doesn't hear productions of Romeo and Juliet and The Merchant of Venice performed in an Italian dialect. It is safe to say that unless one is in Germany, Doctor Faustus is not performed with German accents (one would hope!(.
As to what specific dialect in the English language is used, it will most likely be standard UK English (just because conventionally, for better and often for worse, classics are typically done that way), but it could just as legitimately be American. An argument could be made for Australian given the leads are both Australian, but I doubt that the production would do that, not only because Les Miserables with Australian accents would seem quite bizarre to its target audience, but because it would be ridiculous to expect an entire supporting cast of non-Australians to master the dialect when two Australians already more than adept at English and American dialects are playing the lead.
One would expect that the cast would use the same national dialect, with parallel sub categorical distinctions (conveying "class," regional differences, if need be), to convey that they are compatriots. While the characters are French compatriots speaking French, the actors are not speaking French, but English, which is why it would be quite silly and unnecessary for all of them to affect French accents. (of course this would be different if the film had made a decision (which would have seemed to say the least bizarre) to primarily cast French actors, which it did not).
It is perceived that, for American audiences, a British dialect is understood as being sufficiently European without being too foreign, incomprehensible, or abrasive. There are exceptions to this, of course. But, generally, if it's a movie set in a foreign-speaking European country, everyone will speak in British dialects.
It doesn't help that many European dialects are associated with villainous characters (Nazis, Soviets, any Eastern European dialect... the French).
Most Americans portrayed in non-American films will typically have some sort of standardized accent, too, regardless of where the character is from.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."