Are you going? Probably. Will you regret it? All your life. What not to do, and who you'll be doing it with, by Decca Aitkenhead
"It all started to go wrong with the democratisation of the workplace. That's when the chap from the post room started spewing all over the chief executive's desk. The whole thing is hell."

The hell that will be keeping the agony aunt Clare Rayner busy well into January is the date looming in our diaries: the Office Christmas Party. We are about to spend an evening in the company of our colleagues and several cases of cheap white wine, in the name of festive cheer and camaraderie. We will probably present ourselves at our partners' dos as well. It is hard to find anyone who will not be going to at least one office party. It is almost impossible to find anyone who will enjoy it.

"A good office party is, quite frankly, an oxymoron," says Clare Rayner.

Among the letters making their way to her next month will be the annual flood of angst-ridden confessions.

"They are always the same: 'Do you think my boss will remember what I said? How am I going to make good?'

"And, my God, the number of affairs that begin at the party ... In the cold light of day, it's a horror."

The modern office party is a calamitous occasion. It is a brazen, Bacardi- soaked frenzy, with a tendency for people to finish doubled over the filing cabinet being unwell, or over the photocopier with Mike from Accounts being unwise. At best, it is an awkward affair. At worst, it ends with your P45.

This is a relatively new phenomenon. Until the Seventies, Christmas was usually observed with a glass of sherry in the boss's office or a genteel dinner-dance to which clerks dutifully invited the wife. The likelihood of misdemeanours was scant: first, because workplaces were largely single- sex environments, so although the event might be mixed, thanks to the addition of spouses, the chances of Mrs John Clerk getting up to anything with Mike from Accounts when she'd never even met him before were slim; second, and crucially, there was no attempt to renounce the office hierarchy for the night.

A company director recalls: "Before the Eighties, nobody expected me to pretend I wasn't the boss for the other 364 days of the year. No one asked me to put on a silly hat and show what a good sport I was. Now I'm meant to lark about with them like a fool, as if I hadn't been the one issuing memos the week before about smoking - or the one who might be making them redundant the next week. I know they don't like me - it's a nonsense. And bloody embarrassing."

Many industries used to have a tradition of inverting the hierarchy for the evening. Surgeons would wait on junior doctors at dinner, managers would serve drinks to the sales assistants. But the role-reversal merely served to reinforce the relationship - what made it "funny" was the shared understanding that your boss was your boss, not your equal. It was a far cry from the latter-day pretence that bosses and bossed can forget it all for an instant and have a Good Old Laugh together.

A survey last year by Reed Personnel Services illustrated the results of this ill-advised approach. One worker was fired for punching a manager; a chairman drank too much and ended up in court; a law firm secretary who complained that her boss had touched her breasts (and then consumed a seven-inch chocolate penis covered in cream) was sacked.

"Office parties are laden with sexual intrigue of the most crass and depressing variety," says Susan, an advertising executive in her thirties. "There's a particular kind of drunkenness that you don't find at any other social gathering. It's simultaneously hysterical and maudlin.

"You get these morbid confessionals among the women, and then they go off and seek solace in the arms of the most unsuitable man there, who is invariably married and has usually had a similar encounter with her best friend the year before. So if you've been working there for 10 years, you've got off with everyone."

This fateful combination of free (tax-deductible) alcohol and in-built power relationships has prompted the Brook Advisory Centre to publish a leaflet about office parties. Margaret Jones, the centre's director, explains: "We were getting distraught calls from women, so we put together some, what shall I say, 'tips'. Like, remember condoms, and don't drink too much. We call it a payslip flier: we send it to companies to pop in their November payslips."

Junior women are not alone in feeling under pressure to perform: senior executives must also play their part. They are expected to demonstrate that not only are they hotshots in the boardroom, they can be wacky party animals, too.

"The senior executive will always dance with the fat, ugly woman to show what a nice guy he is," says Susan. "And the really big cheeses are there trying to show that they've got a sense of humour - so they put on a party hat. There they all are, smiling gamely, but rather grimly."

Another important feature is the earnest entreaty to "bring your partner". (Always now, note, your "partner". This can be disastrous. One department store sales assistant duly brought along his boyfriend to last year's do, only to sit through the director's hilarious after-dinner jokes about "arse bandits".) Sadly, as the partners usually neither know anyone nor work in the same field, they have a miserable time. But they have to be produced to prove that they exist.

Even a glamorous workplace is no guarantee of a glamorous party. The fundamental problem - that you are expected to have fun with people you probably dislike - still applies. Alex Payne, a club promoter, says of his former girlfriend's Models One Christmas parties: "I suppose they didn't photograph each other's bottoms on the photocopier - principally because someone else does it rather better all year, for an awful lot of money - but apart from that, it was all the usual stuff."

This Christmas, says Reed Personnel Services, we will see yet more - and more lavish - office parties than before. "Our catering division is reporting the best Christmas for five years - orders are double last year," it boasts, ominously.

They also report a worrying upsurge in "organised entertainment". The Blobendales - a hen-night favourite featuring the unmissable "Blob sandwich", in which a volunteer is squeezed between "tons of fun", are a hit this season.

The solution is, clearly, not to go. I suggested this to one executive who had just detailed why he dreads the whole affair. He was aghast. "Not go? But you have to. If you don't, you'll sit at home all night knowing that you're the topic of conversation."

So go we shall. If you've had Mike from Accounts in your sights all year - good luck.

Blobendales can be booked on 0171-610 1113.