kawaro that is so true. 70% of the population here aren't middle class by any definition, but a lot of people enjoy feeling that they are. It strokes their egos to think there are people "beneath" them.
Traditionally "Middle class" here refers to a number of different traits you must possess, but chief amongst these are a PROFESSION (NOT a trade or skill, but one of the careers that falls into the PROFESSION brackets - doctors, lawyers, architects, teachers, lecturers, etc), average family income above a certain amount, then a lot of bullshit little things like MANNERS and how you conduct yourself!
I personally don't feel I fit into any class - being raised mostly lower working-class/underclass, then having periods bordering on homelessness mixed in with absolute wealth, then finally joining a profession (but sleeping late, working few days a week, and generally acting like a man-child). I take part in certain unsavoury activities, I go to museums and art galleries, some nights I eat at restaurants, others I have very cheap turkey dinosaur shapes to eat. I can't define myself at all using the British class system, and I imagine that many people here feel like mixtures or crossovers. Most however have apparently decided that they're "middle class", due to the fact that their teeth aren't all falling out and their kids aren't starving any more. If there's been a relaxing of the system, they didn't tell me hehe!
EDIT: Sidenote as I think my father is a useful example. He went from criminal enterprise to getting his PhD over two decades of growth. He's evolved as a person, sure, but his values and the way he is are hard to pigeonhole. He looks down on the majority of his friends (who are all working class for the mostpart) for their womanising, fighting, and drinking every weekend, but at the same time has real problems with anyone he perceives as "middle class" (to him this translates as "snobby, finks they're better'n me EH?!?!).
My other half's father is possible the most middle class man I've ever met. He's like the dictionary definition illustration of a middle class guy. However, when Paolo TOLD him he was the most middle class guy we'd ever met, he got really upset and was genuinely shocked. In spite of his fabulous wealth and career, his wine tasting events at his palatial home, his membership of the masons, presidency of the gentleman's club, attitude towards people less well off, overall middle-England-ness, he could not believe that he was anything other than working class due to the fact that HIS father worked in a factory.
Bah, rambling, but CLASS SYSTEM TALK fires me up! Either there are rules, or there are no rules. If no one understands the rules then the system sucks and is irrelevant, if there are no rules then it isn't real. Either way, it's a way of feeling superior to other people who happen to have the same nationality, race, gender, sexual orientation, whatever. You've got to have SOMETHING to hate and discriminate against others for, right?
Dada: The US middle class is actually a lot more inclusive than the UK class of the same level. Hence why people like Homer Simpson, Peter Griffin and pretty much anyone who works in an office define themselves as middle-class in the US. Why US politicians mention them a lot is because it appeals to the largest group of citizens - basically everyone who isn't on welfare/minimum wage work or a millionaire.