A recent survey has confirmed that London now has a multi-culti majority and white, indigenous Brits, who used to form the majority, are running to the surrounding hills; Cotswolds preferably or even the Sussex Downs; if they can afford it.
One reason for this massive exodus is obvious. No normal person can afford a house in Central London, in fact, they can't even afford a no-bedroom garage. The multi-culti majority are quite happy to live in council estates, etc, that surround the centre and have transformed the face of London due to their entreperneurial skills and very colourful imaginations.
Petticoat Lane and other famous markets surrounding London resemble a gathering of United Nations from all over the planet and the days of pie & mash, fish & chips, egg, bacon, beans and a slice of "holy ghost" are now ancient history; just like the Queen.
Meanwhile the ex-white minority spend their evenings down the posh, local, country boozer, peeping from behind their flowered curtains or watching Eastenders on the telly faraway from the melting pot of all nations wondering why?
Another answer to the question is obvious too (amongst others); it's payback time for all of the wrongs that Great Britain dished out to its ex-colonies and Mr Cameron can say sorry a thousand times, but history has a wicked way of "boomeranging" back down the throats of those who perpetrated such crimes.
Maybe several famous streets in London will also have to bow to the new majority and very soon London will have a Blackchapel and a Black hart Lane; who knows?