When entrepreneurs involve themselves in the restaurant business, they tend to cleave to the old estate agent's adage about "location, location, location". Strange, then, that Seven should be situated fair and square in the middle of hell.

When entrepreneurs involve themselves in the restaurant business, they tend to cleave to the old estate agent's adage about "location, location, location". Strange, then, that Seven should be situated fair and square in the middle of hell.

Leicester Square. There is no worse place on earth. Headless pensioners expiring on trolleys in NHS hospitals count themselves lucky that they are not standing in a queue for Häagen-Dazs opposite the Swiss Centre, or having their profile cartooned outside the Odeon while greasy-haired day-trippers squeal like stuck pigs from some naff fairground ride.

Worse still, Seven is situated above Home, the grimmest club in the world. One is tempted to see it as the gates of hell, and the three bouncers who stand outside making sure that the queue goes round the block, even when nobody is inside, as thrice-headed Cerberus standing watch. Except that Satan's dog was an example of one animal with three brains, while these bouncers represent the even more extraordinary phenomenon of three animals managing without even one between them. "Lasciate ogni speranza voi ch'entrate!" one almost expects to see above the door of the restaurant, though strictly, one is leaving hell at this point, rather than entering it. Or so one thinks. But as the door clangs behind you and a woman with a Bella Lugosi look in her eye leads you up a steep metal fire-escape to the lifts, you cannot help but abandon hope.

The main dining-room is long and dingy. You can't see your food (which turns out to be just as well), but you can see the demented, tortured souls in the square. Yes, Big Ben and the Victoria Tower peek out over the tops of the cinemas, in winter, when the trees are not in leaf, but, as vantage points go, I doubt it is what Sir Christopher Wren had in mind.

The clientele derives from that unpindownable cross-section of whom you can safely say that on any given occasion the men will be underdressed, the women ludicrously overdressed. The dress code, in other words, is Blind Date. How does it happen? Why is it that certain kinds of restaurant, like certain kinds of television show, attract bandy-legged men with jeans, trainers and untucked shirts, and women in shoulderless ballgowns, wearing foundation so deep you could plant tomatoes in it?

As it happened, I was not put in the main dining-room, but in the loo. At least, I think it was the loo. Except that it had a view of the cutlery trays and the slops bucket, so it can't have been. But it was a mean, bleak little lobby tucked behind the till, where no waiter seemed to appear for hours at a time.

The menu is simply rubbish. My companion was a vegetarian, which is not a thing I approve of, per se, but it highlighted the inflexibility of what was on offer. There was nothing for her at all, really, the only option being a pear and gorgonzola salad followed by a plain risotto. That was it. Nothing else. What do they expect her to do if she returns - have them again? An unlikely scenario, admittedly, for nobody in their right mind would come back for more.

The gorgonzola thing was made from cheap, slimy cheese, but the veggie liked it. That's veggies for you. My spaghetti vongole was not technically actionable, but the pasta was overcooked and floury, and the juice tasted of butter, not olive oil. Yuk.

Slow-roasted suckling pig sounds such a majestic thing that three slices, each about the size of a credit card, seems doubly stingy. But the pork wasn't bad, and the cabbage stuffed with black pudding was good. The potatoes were terrible. The plate had one of those internal rims designed to keep the margin clean. But the thin gravy had slopped over the rim anyway. The risotto was ordered small, came small (garnished with a greasy thumbprint), and was charged on the bill as large. We said nothing. Better to have as little of it as possible on the plate, to be honest, and hang the expense.

For pudding I had mint panna cotta. You know how panna cotta usually look like a little sandcastle? Well, this one had broken in the middle and fallen over, as if caught by the incoming tide. The waiter plonked it down. "Is it meant to be like that or has it fallen over?" I asked. He said it had fallen over, and walked away.

Head chef Richard Turner has apparently worked with Michel Roux and Marco Pierre White. As what? Did he help them with a bit of plastering? Did the three once collaborate in a neighbourhood-watch scheme?

The best thing about the meal is that it eventually comes to an end. But there is a coup de grâce still to come. They won't call a cab. They have a £50-a-head restaurant in the grottiest location in London, and the best they can do is point you towards a mini-cab company the other side of a river of rubbish, bin bags and drunks.

Sadly, Seven makes no effort to do anything right at all. But then, hellfire and brimstone are not answerable to market forces. If I half-suspected that the punishment for sin was another meal at Seven, I would turn my lifestyle around so fast I'd be in the running for Pope.

Seven 1 Leicester Square, London WC1, 0171 909 1177. Lunch Mon-Fri noon-3pm, dinner Mon-Sat 6pm-midnight. Three course dinner, about £30. Discretionary service charge added at 12.5 per cent. Credit cards accepted, except Diners