My mother-in-law was once a single mother, struggling to bring up two children while working as a teacher in a tough inner-city comprehensive. One day, outside a supermarket, she was approached by a man who was canvassing for election as an MP. When it turned out that she wasn't going to vote for him, he said that she should try living in the real world for a while, that life wasn't all horse shows and dinner parties.

What led him to the conclusion that she lived a life of privilege and ease? Well, she has a posh accent.

My mother-in-law and my wife, who is also posh, claim that this sort of attitude is relatively common, particularly from the likes of me - former working-class university educated sorts. We've had to cage our prejudices towards everyone else but, as soon as we hear a cut-glass accent, we feel free to let them snarling into the light as we convince ourselves that being rude to posh people in some way equates to a political stance.

Is it really possible that posh people suffer discrimination, though? To find out, I decided to become one for the day.

First, I would need elocution lessons. It's a sign of just how unfashionable being posh has become that these don't exist any more in the traditional way. There seems nothing at all for someone who is dedicated to increasing their perceived social class.

This left me with voice coaches who teach accents to actors. Mel Churcher is one such. I was surprised when she asked me what sort of posh I wanted to be. There's more than one kind? I suppose my ignorance reveals a prejudice in itself. Of course posh has strata and regional variations of its own. It just never occurred to me before that it did, just like it never occurred to me that there may be poor posh people, nice posh people, unhappy ones, sensitive ones or even those who have had no opportunities in life before I actually met a few.

“You have to decide if you want to be Received Pronunciation (RP), hyperlect, county, Sloane or medja,” Mel says. “Well, I'm not being Sloane!” I say. I may be opposed to anti-posh prejudice but, by God, there are limits.

Mel says that it will help her to advise me on the most suitable posh accent if she gives me the “hospital test”. This means I have to say the word “hospital”. I do and, surprisingly, she says I pronounce it in RP. Apparently, I blow out the “l” from either side of my tongue, rather than articulating it. I thought RP would be with a very hard and precise “sp” and “l”. Mel says this is a common mistake. When people try to “do a posh accent”, they often overarticulate, leading to the pronunciation of a lady from Birmingham I knew who talked about going “weeding in the garding”. This is the “David Starkey effect”, by which words such as “Parl-i-a-ment-a” and “tissss-ue” are rendered with all their bones showing.

Mel says it's no surprise that I speak a rough RP. It evolved as the accent of people who have followed exactly the path that I did, albeit a few generations before when it was more difficult to get a university education.

“It was spoken in the North of England before the South. In the days of the mills, those were the people who could send their kids to Oxford and Cambridge, and it came from those roots,” Mel says.

So I could just slightly posh up my own accent and get away with that. However, I am nothing if not ambitious. I decide to go county. This is the huntin', shootin' and fishin' accent of the landed gentry. It's characterised by its brief endings to words, clipped consonants and short vowel sounds, probably best summed up by Edward VII's enquiry to Lord Harris, who had made the mistake of wearing a brown bowler at Ascot: “Goin' rattin' 'arris?”

The accent is also a matter of inflection. Nowadays we are all Australians, apparently. We used to say: “Are you going to town?” with a rising inflection and reply: “Yes, I'm going to town,” with a falling inflection. Now it's the other way round, we drop into the question and say: “Yes, I'm going to town,” with a rising tone - as if we're not quite sure of ourselves. Our inflection has gone Down Under.

I absorb what Mel says and give county a go. She thinks I am con-vincing, although she's doubtful whether I can keep it up all day. I am doubtful I can even begin.

My prejudice is revealed when I decide to walk the dog in a posh accent. My plan is to break things in gently, take a stroll along the sea front and call to the dog in a posh voice. I find I can hardly bring myself to speak. Part of me very deeply does not wish to be identified as posh. In the end, I manage to spit it out.

“Reggie!” I shout to the dog, “come here at once, you cur!” I pronounce the short “i” in Reggie and “cur” comes out “cah”. I'm mildly surprised when I'm not immediately beaten up by an angry mob. I'm even more surprised by the behaviour of the dog. He norm-ally pays scant regard to my requests to come away from lampposts, dropped chicken bones and other dogs' nethers, but this time he immediately pricks up his ears and comes lolloping towards me. Is it possible, I think, that the county accent evolved simply as the best way of commanding animals? Does it register in some unheard frequency that dogs and horses feel compelled to obey? I try it again when a particularly annoying alsatian that regularly plagues us comes along. “Be orf!” I say.

It goes away! Better still, its owner, who occasionally tries to engage me in conversation on topics such as difficult parking and Eastern European immigrants, gives me a funny look and moves off as well.

I'm beginning to like this. In fact, as I walk along talking to myself in the way I imagine posh people do. “Splendid day, ideal for goin' shootin'.'' I actually start to feel, well, superior. That's when I notice that I've started walking along with my arms behind my back in the manner of Prince Philip reviewing the fleet. And, come to think of it, there's quite a lot I would like to shoot. Grouse would be a long way down my list, but those park footballers who don't take any of their drinks bottles with them when they leave could benefit from a bit of buckshot; that inappropriately flamboyant old man on roller skates and the local pit bull owners too.

The man at the kiosk of the open-air café barely registers it when, in the manner of Brian Sewell, I request a teacake.

“Would you give me a teacake and cup of tea?” I ask, like someone doing an impression of an owl in a school play. Oh no, Sewell's not county is he, he's “hyperlect”, the level beyond RP that sounds like a Noël Coward impersonation - ironic, since Coward's accent itself was an impersonation of his idea of posh. Still, I am posh, if not consistently posh. The kiosk owner just smiles as he hands over the cake.

The menial folk - sorry, the method acting side of this rather got to me - don't seem at all bothered by my voice. What I need is to locate a good old-fashioned bitter, semiintellectual Marxist. Hence, I try the anti-war group, which has a stall outside the shopping centre. The angry typeface on the posters looks suspiciously similar to that employed by the Socialist Workers Party. Here, if anywhere, I should meet rejection.

“If I wanted to join what would be the entrance requirement?” I ask, pronouncing requirement “reqwaaament”. For the first time I get a reaction, but not the one I expected. The man on the stall almost goes into a panic, as if he is having to re-evaluate everything he holds dear, and he adopts a sort of gulping, fawning attitude. He says there is no entrance requirement as he asks me if I'd like to come to Trafalgar Square on a rally. “Well, I may,” I say. “I must say, I think you chaps do an awfully good job.”

“Thank you,” he says. I can now identify his attitude more exactly. It's not fawning, it's like the one I adopted when I stormed into my local car dealers, demanding to know exactly when they intended to release my car, which they had held captive for a week. They apologised, knocked the labour cost off the bill and said they'd given it a complementary valet. My high dudgeon had nowhere to go. The man has an attitude of disappointed outrage.

“I think I'll come,” I say.

There is a woman in an ethnic-looking hat on the stall, however, who seems ready to explode with anger. “Good! Good!” she shouts at me in a way reminiscent of Arthur Scargill shouting “scab!” and, with a low growl, passes me a form. Clearly I'm not the sort of person she imagined standing shoulder to shoulder with on the barricades, although the literal meaning of what she says is welcoming.

Being posh is strangely empowering. I ask a group of teenagers to pick up their litter and they do. No “posh t***”, no talking back. Admittedly, I feel empowered to approach only useless middle-class Goths, not the sportswear-and-knife boys, but it's something I would have never done before.

The day goes on without incident. In fact, people seem quite cheered to meet a toff. I do notice two girls at the sandwich shop giggling at me, but it seems quite good natured.

Towards the end of the day, though, I do have one unusual reaction. I'm in the Pavilion, showing a friend from out of town around, when a very well-dressed American lady comes up to me.

“Does your family still live here, or do you have other homes?” she asks. “My family lives in a one bedroom flat in Coventry,” I say.

“Oh,” she says. “I thought you owned the place. You speak beautifully.”

No one has ever said that to me in my life before. And then a dreadful thought strikes me. I actually like being posh.

Pronounced differences

RP The “neutral accent” of Radio 4. SingING, not singin'; little, not li-ool.

Hyperlect As RP, but more identifiably posh. Brine trisers for brown trousers. Princess Enn, not Princess Anne.

County The accent in which you marshal hounds and warn poachers just before you shoot them. Huntin', shootin', fishin'.

Sloane A lazy version of county, slurring its pronunciation under the influence of estuary English. Yaah, not yes; riii, not right.

Medja Not quite as languorous as Sloane. RP, rather than county, with some urban overtones. Gestures towards the glottal stop without quite going so downmarket. Tony Blair. Cool, yeah?

Explore Women

• Fashion

• Beauty

• Diet & Fitness

• Relationships

• Families

• Celebrity

• Body & Soul

• The Way We Live

Times recommends

• Kiss me chick
• Our little emperors
• Five perfect minibreaks in Britain