This being Britain, it's more that the Lower Class fighting against an even lower class (and for most English, immigrants are the lowest class there can be since the English generally think they're inherently superior to foreigners) is fine, but the Middle and Lower class disturbing the interests of the Upper Class is unacceptable.

Britain is an incredibly classist country, not only by US standards but also by European standards and it's a lot easier to understand the dynamics of the use of Power over there if you look at the social class of those involved.