Reader, the very fact that you are asking me how to get a table at the Ivy suggests that you are not as up to speed with your fashionable London restaurants as you might be. Tsk, tsk. Although still a desirable place to dine, even the Ivy themselves would probably admit that their reign as the hottest spot in the capital is long over. That accolade now belongs to Scott's, the revamped Mayfair fish restaurant, which is so deliciously courant that even Nigella admits she spends 'half my life' on the pavement outside it keeping her husband company as he has a crafty fag. Divine, no? Especially as those keen to make a social impact need now only loiter near Scott's front door, pretending to have nipped out for a gasper between courses. This could, at the very least, get your picture in Hello! and you will certainly impress any passing friends with your fashionable restaurant-going skills.

By fashionable restaurant, I mean the kind of place where power, money and glamour break bread with celebrity, notoriety and fame; where the paparazzi on the pavement are as much a fixture as the 12 per cent service charge, and where there is a good chance you might bump into Kate Moss, some bloke who's been on Friday Night With Jonathan Ross and a very expensive fishcake. It's as simple as that. Except it isn't. London is a tribal city, where different social groups are clannish about the restaurants they support and use, much in the manner of football supporters. Eurotrash love the Cipriani and La Petite Maison, hedgefunders and the new Russians prefer stratospheric Japanese fusion at Zuma, while every frisky, carb- conscious heiress west of Park Lane goes to Tom's Kitchen at least once a week for a burger, please, and hold the lovely buns. She usually means her own, not the ones on the plate, but that is not our concern here.

Now that we have established the cultural landscape and made at least one inappropriate joke, let's move on to practicalities. So how do you get a table at the Ivy, or any other hotspot? Obviously, the easiest way is to become famous, and preferably not by chopping everyone in your street to pieces with an axe because you don't like Tuesdays or have snagged your new Fogal tights. Yet if you can get onto the front pages in a semi-wholesome way before 8pm on Thursday night - London's most desirable and consequently most unattainable booking slot - you will be in like Flynn, and I mean Lara Flynn Boyle, not Errol. Like it or not, when it comes to restaurants, celebrity is the Soviet-style Zil lane that leads straight to the best table in the house.

Some get annoyed when restaurants give preferential treatment to famous people, but I have come to realise that it is their prerogative to run their businesses exactly as they see fit. No one has to buy into the whole crazy nonsense, or put their name on a waiting list if they don't approve, or appreciate that celebrities are good for trade. You know that section at the front of this magazine? Where someone from OFM rings up a restaurant pretending to be a celebrity and tries to get a table? It drives me nuts. If there ever was a point to prove, OFM proved it on day one, when the A-list celebrity got the table and the poor old deadhead Z-person did not. My point is, is it fair to clog up booking lines pretending to be Kylie, when the real Kylie might be trying to get through to fix her lunch? That is the kind of thing I worry about.

Before you ask how can I get a table at the Ivy, you might want to ask another question; why do you want a table at the Ivy in the first place? Why struggle to gain ingress to any restaurant that may make it plain that it does not want your custom? There will certainly be another restaurant in the vicinity that will quite possibly serve better food at a cheaper price, and have a more egalitarian approach to its customer base. If, however, you have your heart set on gourmet glitz and the fashionable restaurant at all costs, then I offer the following. In the short term, be flexible about booking times. Steer clear of peak dining traffic. Accept after-theatre. Call the restaurant on the day to see if any slots have opened up; you might be surprised at how effective this can be. If you are particularly charming and attractive, go and have a chat in person about future bookings. Never telephone during service. If your ego can take the possible refusal, turn up early and smartly, and request a quick-ish dinner. In the long term, the best method of securing a table anywhere is to become a regular. It might even put you ahead of Nigella in the pecking order. But don't count on it.

· Read Jan Moir's restaurant reviews at areyoureadytoorder.co.uk.