Brighton Museum, which reopens today glittering after a £10m rebuild, is displaying the most outrageous piece of black propaganda. The council should padlock the offending gallery at once, before word spreads and destroys the 250 years of spin that transformed a scruffy little fishing village into Soho-on-Sea.
The old museum was one of the most beloved in the country, with nationally important collections including the ethnographic and decorative arts, and a joyous sprinkling of the downright weird, all shovelled into a bewildering building full of dusty corners and dead ends. There was something surreptitious, about slipping in through the dark doorway out of the roaring traffic on Church Street.
The entire museum has now been turned back to front, and by smashing through the wall of what was the bar of the Brighton Dome, has gained an exuberant new entrance from the Royal Pavilion Gardens. The beauty board, Artex and hessian have been ripped away, and windows unblocked to let light stream in and reveal the dotty splendour of the building itself, with its soaring Victorian Gothic ceilings and sumptuously carved door frames.
Director John Roles knew he was walking on eggshells by accepting the lottery shilling, and by laying a finger on the museum in a town grossly over populated with designers, artists, collectors and heritage fogeys. And, sure enough, he has already been most bitterly criticised. There are savage complaints in the new visitors' book: "Very very fab indeed - however we do need the pussy back."
It turns out that the single most beloved object in the museum was only 20 years old, a giant papiermache white cat decorated with blue willow pattern, which pleaded for donations and miaowed its thanks. It was made by the museum's own design team, and voiced by a junior curator. It is gone, although the museum is trying to get it back.
The cult of Brighton, brilliantly dissected in both the museum's new Images of Brighton gallery, and the temporary exhibition on Brighton on Film, has been remarkably consistent over the centuries, from Georgian caricatures to 1990s club flyers. Frolics by the sparkling waves, with a grimy undertow. Not quite wholesome, not just fresh air and bracing sea dips. Fun with a frisson.
An 1806 watercolour shows a smart young woman leaning over a balcony, watching the promenading crowds. She does not look as if she is seeking a companion for a nice walk. A 1999 card, collected by curators from a phonebox in the town, promises: "Transexual - Tits and Tackle all in one, twice the fun."
But style is always important - better to be dead of cold in the whipping wind than uncool. How can you doubt it of a town museum guarding Fatboy Slim's shirt, an original version of the much copied Mae West sofa by Salvador Dali, and a Lambretta scooter? (A mod, interviewed for the oral history archive, insists reports of the infamous bank holiday mods and rockers riots were grossly exaggerated: "No real mod wanted to roll around in the dirt.") Every gallery in the transformed museum breathes stylishness, from the dark treasure chest of World Art to the blaze of colour in the Performance and Fine Art galleries - until you come to the outrage in the far corner of the first floor.
The costume collection is one of the few that is back in its original home, but nobody would recognise it. A dingy black box has been scoured back to its startling Victorian bone structure, and painted white. The original collection, which included Lady Holmon's truly staggering trousseau underwear (her camiknickers came embroidered with ballerinas, ballroom dancers or horses and hounds, the latter set reserved for her wedding night as a delightful surprise for her fox-hunting husband) has been expanded with newly collected street fashion, including a handsome parade of punks, hippies and Goths.
And then you come to George IV, who more or less invented Brighton: scandal, escapism, teenage rebellion, reckless extravagance, wild architecture, wilder parties, he had it all. And just look what Brighton did for him in return! The case contains a selection of garments belonging to George, which have never been on display before. They are rare survivals - his wardrobe was so vast and so sumptuous that it was auctioned after his death. There is a shirt, a very large shirt, but 18th-century shirts were voluminous. Then there's a banyan, a quilted chintz oriental dressing gown, a sexy and beautiful garment tailored for him when the teenager was regarded as one of the most handsome princes in Europe. It is displayed fastened, slim as a cigarette - but open it and you can see the panels let into the attached waistcoat for the rapidly expanding royal.
And then there are his breeches, dating from 1827, just three years before his death. They are stupendous, gargantuan, big enough to fit Fatboy Slim and the Lambretta. Terrifying - and all Brighton's fault.
· Brighton Museum, Church Street, Brighton (01273 292882).
