With the exception of about 4 people in cornwall, the english only speak english.

Often, not even that.

Snark aside, there would be a lot more interest in a split along racial and religious lines. Little Englanders don't much like brown people, and - realistically - sometimes vice versa. We already have areas of London with strong racial and cultural characteristics but - luckily - there's no precedent for them to try to act independently.

Practically, they really couldn't anyway, not even if they put up barricades. But if we ever had a BNP-type government I wouldn't be even slightly surprised to see the bigger cities splitting up spontaneously into racial ghettos. That would be a very bad thing, but it's a lot easier for people here to imagine that than an England split into

Traditional English regional colour is often really just a fabrication of the heritage and tourism industries. Areas like the Cotswolds have a distinct flavour, but there's nothing political about it - it's about the physical countryside and different kinds of pubs and cottages, not about dialect and identity.