This is the progressive liberal view of multiculturalism and it's been taken as read in the UK since the war, for two reasons. The first being that the two great wars of the early 20th Century had at their root ethnonationalism, the same could be said of what's happening in Ukraine now, the Balkan wars, tribal wars in Africa and so on, ethonationalism is seen by progressives as a scourge and multiculturalism is its cure, but this has happened very rapidly. If you were able to travel back to any time before say 1950 and talked about multiculturalism with a bloke in the pub anywhere in the UK, people would have thought you'd gone bonkers, particularly as they'd just finished fighting a war to preserve this island race.
The second reason is labour, folk from the ex colonies here, the gastarbeiter in Germany and so on were all needed for post war construction and once you're hooked on cheap labour or skilled labour on demand trained at someone else's expense there's no going back, despite what the Brexiteers might say.
So here we are, as Farage says no one asked the British people about this and while he's wrong about almost everything he's not wrong about that, as for....
"The UK has always been a product of multiculturalism, it's been shaped by centuries of migration and cultural exchange. The national identity has never been fixed, it evolves through diversity."
That is the off the shelf reply and liberals applaud it every time it's wheeled out, but it’s simply not true, at least not in the way you frame it. The UK for much of its existence has been a mixture of Anglo Saxons, Normans, Celts, Danes and so on, but we’re talking tiny numbers by post war standards, prior to the Second World War the ethnic and cultural changes in the UK were on a glacial scale compared to the numbers and rapidity we see today, that is simply a fact, by stating “
The national identity has never been fixed, it evolves through diversity” it does not, it evolves by integration, and that's true everywhere, go ask the Hutu and the Tutsi about a national identity evolving through diversity, stay closer to home and go to the old Lancashire mill towns, go to Bradford and tell me how diversity there is forging a new national identity.
Diversity does not, in of itself create a strong national identity, if anything quite the opposite, homogeneous societies have the strongest national identities and on the whole they're the most stable and harmonious societies.
Put simply there can be no evolution of our national identity without integration, and there can be no integration without something to integrate with. A strong national identity, albeit of a particular kind, is prerequisite to a stable and functioning multicultural society, but in Britain we've failed to identify a distinct national notion of belonging.
A cohesive notion of a multicultural society cannot be based simply on the idea that we should respect other people's values. It also requires a positive articulation of the values underpinning such as society.
The key word here is "cohesive". Forget slogans like "diversity is our strength" coz without a strong glue it does precisely the opposite.