With more than 60 languages now spoken among its inhabitants, the UK has become one of the world's most exciting and diverse cultural melting pots.
So, bearing this in mind, alongside statistics showing that by next year the disposable income of ethnic minorities is set to hit £300 billion, why does the question of whether agencies and clients can, or even want to, advertise to this group keep coming up?
It can be argued that compelling commercial messages transcend racial differences with their power to motivate a Bangladeshi in Bradford just as much as a Caucasian in Cambridge.
However, the IPA's Ethnic Diversity Group claims it isn't that simple. In the second of its periodic reviews of how well adland is getting to grips with an expanding multicultural society, the group suggests that, as far as advertising is concerned, one size definitely doesn't fit all.
It warns that unless the industry takes note of a rapidly evolving UK ethnic landscape in which established Afro-Caribbean and Asian communities have been augmented by large numbers of Eastern Europeans from an expanded European Union, it risks being seriously off the pace of change.
If it all sounds familiar, that's because the message hasn't changed significantly from when the group's first report was published in 2003. Trevor Robinson, the group's joint chairman and the founder of Quiet Storm, admits little has happened in the intervening period.
"Agencies are fearful, so they stick to what they know - and the economic crisis has made it worse," he complains. "I find it bizarre that a report of this kind still has to be put in front of people."
The report presents a picture of an ethnic minority community that is constantly evolving with younger generations much more integrated into British culture than their elders. All are heavy users of mobile phones - and are very loyal customers to particular brands - as well as being compulsive viewers of cable and satellite TV, watching ethnic programming the main channels don't provide.
They are also more likely to own a new BMW or Mercedes than the UK population as a whole.
"Multicultural communities will be more visible and influential as they climb the business and corporation ladder," the report concludes. "As budget holders they will have more say. As the forecast increases in numbers, they will also want to feel they are being communicated to, so targeting diverse groups and communities is going to be a given for all successful UK brands and marketers."
Some, though, suggest little will change within agencies until ethnic minorities, currently representing 8.9 per cent of the industry workforce, occupy enough senior positions to influence events.
"Nothing much is going to happen while they're still fixing computers in the IT department," Glen Yearwood, an ethnic-focused communications consultant, says. "I'd like to think agencies are getting better at targeting ethnic minorities but I don't see much evidence of it on my TV screen."
Nevertheless, senior industry figures bridle at the accusation that, when it comes to marketing to a multicultural Britain, they don't get it. "Advertising that's done well is based in truths that aren't just skin-deep," Damon Collins, the executive creative director at Rainey Kelly Campbell Roalfe/Y&R, says.
Agencies also question whether ethnically targeted advertising makes any sense in a multicultural nation. Guy Hayward, the JWT UK group chief executive, says it's more important for agencies to understand a brand's audience and its market.
"Culture, race or ethnicity are important but they are only part of that understanding," he points out. "It has to be smarter to focus on truly understanding your consumer than to segment your audience by culture or ethnicity."
Others, though, think agencies are deluding themselves. "We've enough evidence to show that members of ethnic minorities look at ads in a very different way," Patricia Macauley, COI's head of cultural diversity, claims. "Many don't like ads that are too clever and they can easily miss the message."
Some advocates of better targeting of ethnic minorities cite the example of the US where there are a significant number of minority-owned agencies that focus on the country's huge African-American and Hispanic communities.
Others claim that situations in the US and the UK are markedly different. Here, ethnic minorities account for just 8 per cent of the UK population, although that figure is expected to reach 15 per cent by 2016. Moreover, just a handful of specialist agencies work in the sector, a number of them relying heavily on COI assignments.
What's more, the size of US ethnic groups is often matched by the advertising. Probably the best recent example of that is "The Great Schlep", the Droga5 campaign encouraging young Jewish Democrats to flood into Florida to encourage their grandparents to vote for Obama.
"We'll never see anything on such a scale in the UK," Danny Brooke-Taylor, the executive creative director at MCBD, remarks. "We're a homogenous little island so the emphasis will always be on overarching brand messages that can apply equally to any group."
Major companies support this view. Ian Armstrong, Honda's head of customer communications, who commands a £50 million annual adspend, says: "It's not a conscious strategy. It's partly down to money. To target ethnic minorities would mean fragmenting our media plan. But we also believe that people will buy into the Honda philosophy irrespective of their ethnic background."
Nevertheless, ethnic minorities are attracting the attention of advertisers such as mobile phone companies. Yearwood, whose diversity unit was set up as a joint venture with Universal McCann to target ethnic audiences for advertisers, is working with General Mills and two other high-street brands.
But he stops short of suggesting mainstream advertisers start putting more business with specialist ethnic agencies. "That would be like a 'sympathy vote'," he says.
Yearwood, a second-generation Afro-Caribbean, accuses agencies of not doing enough research enabling them to tap into "new audiences". But he predicts the 2011 Census will act as a wake-up call when they realise the size of Britain's ethnic minority population.
It's not that targeting of ethnic groups by big advertisers doesn't happen - it just seems that most of it is by government agencies. MCBD took advantage of Ramadan, the Islamic month of abstinence, to run a press campaign for the NHS reminding Muslim men that this was an opportune time to quit smoking, while Abbott Mead Vickers BBDO recently scooped a clutch of awards for its anti-knife crime YouTube campaign for the Metropolitan Police.
More commonly, people from ethnic minorities will find themselves the primary audience for a campaign even though that wasn't its intent.
Wieden & Kennedy recently ran an initiative for Nike to build loyalty among young urban footballers. "Obviously youngsters from ethnic groups are going to make up a large part of the audience for such a campaign," Neil Christie, the W&K managing director, points out. "But we didn't necessarily set out to target them."
Meanwhile, agencies will take a lot of convincing that multicultural Britain is passing them by. "How exactly are we missing out?" Collins asks. "Because if we are, I'd like to see the evidence."
London houses the largest number of ethnic minorities and Eastern Europeans, and is home to people from 189 out of the 192 countries recognised by the UN. The largest number of ethnic minorities live in Newham (68 per cent).
The median age for ethnic minorities is 27 compared with 40 for their white counterparts.
The average Bangladeshi household contains 4.5 people, followed by Pakistani (4.1) and Indian (3.3). The smallest households are White Irish (2.1) and Black Caribbean and White British (2.3).
Black Minority Ethnics (BME) make up 11 per cent of the UK's working age population. This is valued at £3.26 million. Black Caribbean and Indian groups exhibit the highest rates of economic activity (77.7 per cent each). White Indians exhibit the highest rate of employment (71.3 per cent).
The projection for the disposable income of ethnic minorities is £300 billion in 2011. The Polish pound is worth in excess of £4 billion. The Eastern European pound is worth £8.4 billion.
Ethnic groups are keen users of new technologies and 60 per cent are more likely to have cable and satellite TV to view programming associated with their own culture.
275,000 ethnic minorities run small businesses that contribute £20 billion to the UK economy. In London, there are 66,000 ethnic-owned businesses employing 560,000 people and with a turnover of £90 billion in sales. Their business performance outstrips that of their white counterparts.