After the election wipe-out, anyone in search of conservative values should head for the reassuringly traditional Wiltons

A dear old uncle of mine once said to me, "You should never walk into a place as if you owned it. You should walk in there as if you disowned it." He worked for most of his life in the Foreign Office, where a certain authoritative bearing comes naturally, and though I've always liked the sound of his advice there are still places I enter with a certain flutter in the heart and a tremble in the gait. Places such as Wiltons, the venerable fish restaurant in St James's which has been a favourite of peers, plutocrats and old-shoe patricians since it first opened its doors as an oyster bar on the Haymarket in 1742. Over the years it metamorphosed into a restaurant, shifting premises twice before it settled in Jermyn Street.

Arriving for lunch the day after the general election, I wondered briefly if the Tory hangover would infect the mood of the place ­ some grandee face down in his turbot, perhaps ­ but I could detect nothing beyond an air of hushed Edwardian propriety. Indeed, this is a restaurant oblivious to the vagaries of political, or any other sort of, fashion. Impossible to imagine the euro gaining a foothold here; they appear to have only recently recovered from the disappearance of the guinea.

Wiltons has recently had a makeover, though, according to the one regular among us, the refurbishment amounts to a new carpet (Wilton, presumably) and a fresh coat of custard-yellow paint on the walls. Everything else looks as if it's been around for a very long time, from the green velvet banquettes to the pleasant jumble of portraits, etchings and prints on the walls.

The wine list is short and mostly French. I chose the one South African white on offer, a Hamilton Russell chardonnay, crisp, melony, with a hint of oak, and at £30 one of the more reasonably priced. The menu makes few concessions to culinary trends, basing its appeal on a solid, no-nonsense medley of fish and seafood, with a small selection of grills for those who can't do without red meat. The emphasis is on freshness of ingredients and simplicity of presentation; grilling and poaching are favoured methods. There's nothing fancy here ­ nothing, that is, apart from the prices.

The late Alan Clark MP, having braved a fracas with the unemployed of Leicester in April 1984, recorded this guilty afterthought in his Diary: "I thought what Soames and I could spend between us in a single meal at Wiltons." I see what he meant. You could get off to a flyer with lobster cocktail (£16.25), pâté de fois gras de Strasbourg (£19.50) or wild Scotch smoked salmon (£22.25); if they seem insufficiently seigneurial you could trade up to a 2oz helping of Royal Beluga caviar (£99).

We chose more conservatively: two of us had a wintery but delicious lobster bisque, which a waitress enhanced with a double squirt of cognac. Victoria had a dainty helping of avocado and crab and considered it fine, though the observation that "it's a real Abigail's Party dish" seemed unarguable. Matthew called his dun-coloured soup "rich, strong, greaseless". And what is it, exactly? "I've no idea." The bill indicated that it was beef consommé. The half dozen oysters I also ordered never arrived, the only blip in what was otherwise blameless service; in any case, by the time Giles had explained to us that oysters in June were laiteurs, denoting the milky texture that comes of their reproductive juices, nobody much felt like eating them anyway.

For main courses, Matthew and Victoria had liver and bacon, a dish I remember with loathing from childhood; one minuscule mouthful of the liver, with its cloudy taste, acted for me as a repulsive kind of madeleine. But they loved it. Asked to explain what makes "good" liver, Matthew considered: "Thinly sliced, not fatty, and it must be moist" ­ criteria that today's meat happily fulfilled. Giles, having forsworn meat for the last three months, was unable to resist chowing down the slices of liver that Victoria couldn't finish. His own choice, smoked haddock kedgeree, was spicy, comforting and ideal for an election night hangover. I had the char-grilled tuna on a piquant tomato, cori- ander and red onion salad, a nicely firm bit of fish.

The maitre d' and his mostly Italian staff had been perfectly genial in their welcome; not so our fellow diners. Matthew and I, in our best bib and tucker (jacket and tie for gentlemen, of course) had barely sat down before we felt the chill gusts of disapproval wafting from an adjacent table. While one elderly gent fixed us with a look of immoderate truculence, Matthew had fielded the glare from another table behind me. Shielded from further inspection by the two later arrivals to our cosy booth we'd forgotten about the aggressive starers. Yet a new menace lurked. As Victoria said, "You'd think the one great advantage of being here rather than All Bar One would be no mobiles." Yet there he was, a heavy-bottomed diner droning into his phone.

We turned to pudding, a selection of English nursery favourites including sherry trifle, crême brulée, bread and butter pudding, and strawberry and almond tart. Two of us had a go at the summer pudding, but our hearts weren't in it, and the bland sogginess of the dish became a chore. With two glasses of a toffeeish Sauternes and four coffees (double espresso a cheeky £4.10), plus the three Bloody Marys we had to start, we ended up paying around £75 a head, service included. I'll time my next visit for Sunday lunch when a set menu of three courses is offered at a hugely reasonable £19.75.

Wiltons, 55 Jermyn Street, London SW1 (020-7629 9955) Sun-Fri lunch 12-2.30pm, dinner 6-10.30pm (closed Saturday). All major cards accepted. Limited disabled access.