I don't have any identical comparisons of politeness in London and the rest of the UK, but subjectively I do feel people in London are more likely to hold doors, let me skip queues, etc. There's just more of a feeling that we're all trying to navigate life in the city together, rather than gatekeeping each other's presence in it.

It's even more noticeable with people who are paid to be polite: bar and waiting staff, the folks working at Tesco, pub security, the kebab man. I walk into a pub in the middle of nowhere in England, they treat me like I'm intruding or inconveniencing them. I do that in London, they just ask "What are you having love?".

There is definitely a lot of veiled and outright racism and xenophobia though. I've heard things like "your English is actually pretty good" (I was a BBC journalist, it's better than theirs), "at least you're not on benefits", "at least your people are not as bad as X". I've never been told these things in London.