National identity? Which national identity would that be? The national identity the Romans gave us when they settled here? The national identity of the Anglo-Saxon invaders? The national identity of the Normans?
We're a nation of settlers. Whatever indigenous population there was that didn't get wiped out by the Romans were killed over a thousand years ago by the Saxons. Our monarchy is descended from German heritage. The Queen's husband himself is Greek. Our own language is a hodge-podge mix of German, Latin, French, and whatever other language we could mug for loose change. Our national dishes were all either invented elsewhere or invented by immigrants. What national identity are we supposed to have that doesn't acknowledge the fact that the entire country was built by people coming from other countries?
Can I frame this post, put it in my living room and the next time someone comes home while we drink good bourbon I can pull out a pipe and say "You know... I was there when he said that"?