By Vivian White
BBC Panorama reporter
Panorama visits Blackburn in Lancashire to investigate how increased separation and segregation between Muslim Asians and whites is dividing communities.
People share the shopping centre - but they're not shopping together
Blackburn presents a stark example of a difficult, national problem.
For all the hopeful talk about "integration", "multiculturalism" and now "cohesion", the reality on the ground appears to be that Britain's Muslim Asian community and its white community have few points of contact, and that the white majority often feel they share little in common with the growing Muslim Asian minority.
Of course there are hopeful exceptions, but Blackburn - where Muslim Asians on the last census made up 24% of the population and whose local council takes the issue very seriously - demonstrates clearly what the problem is.
Anyone who goes to Blackburn's town centre, and takes a look around, will see that whites and Muslim Asians are sharing the shopping centre and that everyone is behaving perfectly courteously to each other.
So what's the problem? Well, look a bit more carefully, and you'll see that they are both here doing their shopping - but they're not shopping together.
They're nearly always shopping separately. And that's the typical pattern here.
There's very little casual, social association between whites and Muslim Asians. There's an obvious geographical separation.
The areas originally settled in the 60s by immigrants from Pakistan and India are clearly defined.
And in the other parts of town where the communities appear to be "mixed", there's little actual mixing.
Ted Cantle reported to the Home Office on "parallel lives" after the riots in Burnley, Oldham, and Bradford in 2001 (there were none in Blackburn).
He says of the town: "There is not just simply residential segregation, but there is separation in education, in social, cultural, faith, in virtually every aspect of their daily lives, employment too."
Blackburn's MP Jack Straw, a senior member of the government, puts it like this: "The risk is of separate communities, and of people breathing the same air but walking past each other."
The problem that Panorama observes cannot be simply dismissed as "racism", although there will be racists, inevitably, on both sides.
What differentiates the communities is not just skin colour but a more complex combination of race, religion, and language and culture, and these factors added together are a recipe for social separation.
And the phenomenon of so-called "white flight" is one result.
Blackburn's original Pakistani and Indian immigrants came to the town seeking work in the 60s in what was then the booming cotton industry.
Many of them spoke little English and they settled together in the town, buying the cheap terraced housing they could afford.
So this then became an "Asian" area. And as their numbers have expanded they've become more prosperous and moved to other areas. But many whites have moved out in response. This is "white flight".
As some Asians see the process, when they seek to integrate and live with whites the whites avoid them.
Then, to add insult to injury, they complain that Asians don't integrate. An Asian talks about taking chocolates round to his white neighbours, who then avoid making eye contact with him.
"I don't know," he says, "I find that a little odd."
And Jack Straw says: "It's been striking in the last 10 months or so the number of Asian people who... have expressed resentment to me about how they feel they've been treated when they've moved into white schools, or moved into white areas."
But as some whites see it, these new Asian neighbours bring too much change to the areas they move into.
Local pubs close, different food is sold in the shops, and at school many of the pupils now come from homes where the language spoken may not be English.
Meanwhile more and more young Muslim women, not just in Blackburn, are wearing the veil - an issue already controversial and made even more so when Mr Straw described it last year as "visible statement of separation and of difference".
A white man, living in the same area, sums up the concerns many whites feel: "We're slowly getting swallowed up, and we're losing our identity.
"We should work more together," he says, "and keep the place as it is - English."
And, as Ted Cantle makes clear, separation and segregation is not just a problem for places like Blackburn.
"It exists as a problem, to some degree or other, throughout the country, and it may be in small pockets and neighbourhoods within larger cities like London and Birmingham and therefore not quite so evident.
"It might be whole boroughs or whole cities, but to some degree or another it exists. There is some degree of separation or segregation in most towns and cities."
Panorama deals openly in this programme with a topic many in both communities have been too nervous to discuss, although it's a discussion which the local council in Blackburn has itself promoted with its "100 Voices" dialogues.
The prospect, otherwise, is of even greater separation. A white Blackburnian says, regretfully: "You'll end up with Muslim Asian towns, you'll end up with white British towns."
An Asian Blackburnian agrees: "I fear that my children will end up living like apartheid in South Africa."
Panorama: White Fright will be broadcast on Monday 7 May at 2030 BST on BBC One.