CONSIDERED in sobriety, a Christmas office disco lunch is a startlingly horrible idea, combining disparate resonances of 'with-it' afternoon parties for 11-year- olds, and those places in Soho where you can watch sleazy cabaret shows at 10 o'clock in the morning. Disco dancing with colleagues in the afternoon seems unnatural and wrong.

At 4.30pm on a weekday last week it was indeed surreal to find employees of London Underground leaping and pointing rakishly into the air to 'Ride On Time' in a restaurant in Holborn in London; yet for all that, they seemed very much at home underground in the semi- darkness, and were clearly having a rare old time. As one young man with a ponytail explained, 'It's better than just all sitting round having lunch together.'

Excellent point. The office Christmas lunch has rather crept up on us as an alternative to the evening Christmas party. But when left to its own devices, un- mitigated by discos or karaoke, its comparative disadvantages are huge.

You can see why managements like to keep festive celebrations out of the building, to prevent staff abusing the corporate furnishings and fittings in an unseemly way. The tale still circulates in independent television of the senior arts executive caught during an in-office party 'discussing financial affairs' on the carpet with a secretary, who, thinking quickly to avoid identification, gaily popped a wastepaper basket on to her head.

Once outside the building, the good thing about evening drinkipoos is that everyone can freely flirt or start affairs with the people they have been fancying all year. It is no good at all when you are trapped round a table for five hours. The need to sit next to the right person is so overwhelming that there is always an awkard hanging around at the start, followed by an unseemly dash for the right seat. On the rare occasion when you end up beside the person you like most rather than least - what then? The hours of enforced social chat following the hand-on the-knee manoeuvre can create an entire gamut of first love, disenchantment, rows and recrimination in microcosm before the romance has even got off the ground.

Frustrated in their desire to start affairs, drunken Christmas Lunchers tend to turn instead to telling each other that they know about the affairs they are already having. A friend of mine's career is still recovering from her having confided understandingly to her boss, 'We all know that you're sleeping with Sarah' on such an occasion. All this adds to the already strained atmosphere of an extended family, riddled with sub-texts and tensions, having to pull crackers, wear hats, and eat repulsive potatoes together in aid of festive fun. Huge meals in restaurants are rarely a success at any time, with vast expanses of table inhibiting general chat, and the threat of the Bodmin hanging over the proceedings. The Bodmin, according to John Lloyd and Douglas Adams' Meaning of Liff (a dictionary of vital words which didn't exist before), is the difference between the total of a restaurant bill and the amount the assembled diners cough up. Making everyone pay beforehand is even worse. People are sober then and resent forking out garish sums to eat with the people with whom they eat every day anyway.

Small wonder that everyone turns gratefully to drink, albeit filthy house wine, as the sole festive novelty. The essential difference between a lunch and an evening occasion is not that people drink less, but that they start drinking earlier. A hangover which takes hold at five in the afternoon is not good. It can lead to widespread crying in the office, and figures slumped over desks sporting expressions of mute loathing.

The solution which often presents itself is simply to carry on drinking. 'Oliver', a still- shocked employee of a small publishing office, described last week's Christmas lunch in a numb monotone. It began in a restaurant at 1pm and ended in a pub eight-and-a- half hours later, when three members of staff were arrested for causing a table to disintegrate, removed in a police van and locked in a cell. Happy Christmas or what?