MICHAEL FLATLEY is a cult. In Manchester on Thursday night, 2,000 acolytes got to their feet and cheered their allegiance. Since his departure from Riverdance, Flatley has been mobilising a splinter force for Lord of the Dance, another foot-stomping showcase of Irish talent. The title suggests Christification, and even if he'd started blessing Bosnian orphans with the touch of a heavily insured toe, no one here was going to attempt any Cockeresque protest. Flatley's mythographic publicity machine is also pushing him towards deity status. The programme notes take the tone of Tibetan monks congratulating themselves on the choice of a new Dalai Lama: "Whatever spark was ignited in Michael Flatley at conception or birth has grown into a mighty and many-tongued fire." The posters offer him semi-naked within a different iconographic framework: here he strikes the attitude of a fascist discus thrower, a Celtic symbol blossoming from his left armpit. Even the National Geographic Society has joined in, naming him as one of the world's Human Treasures. Not only is he a demi-god, he's an all-dancing Site of Special Scientific Interest.

But as the show opens, with a leprechaun miming to a synthesised penny whistle, it's clear that something less than Olympian is on offer. A portcullis rises and Flatley whirls on in a miasma of dry ice. Clad in a clinging gold lame tunic that gives him nipples like Reeves and Mortimer's Mulligan and O'Hare, he earns a massive round of applause before his feet touch the ground.

And then the plot of the piece gears up. We're in a Celtic Twilight Zone that owes as much to West Side Story as Druidic lore. Our Michael presides over the Warriors, a clan of black-clad bermenschen who enjoy a special relationship with elves, and a deadly rivalry with the Warlords, a second clan of black-clad bermenschen distinguished by their negative attitude towards the aforementioned elves. The Warlords, led by the snarling Don Dorcha the Dark Lord (Daire Nolan), terrorise an elf, callously breaking her magic wand. (Bizarrely, Flatley repairs it by sticking it down his trousers.) I was confused until I returned to the programme notes: "The little spirit travels through time and space to help the Lord of the Dance protect his mythical people. On an incredible adventure, they encounter love, desire and danger." So that's what was happening.

The piece has a surprisingly sexual emphasis, something that didn't appear to irk the noticeable number of children and nuns in the audience. Flatley spends much of the time showing us his sweaty belly, his chanticleering sometimes making the production seem like an over-elaborate round of Man O Man. Indeed, much teeters on the brink of smut. At one point, Morrighan the Temptress (Gillian Norris) enchants the chorus of colleens, causing them to strip to their underwear. Things have moved on since the audience of Playboy of the Western World rioted at the mere mention of slips.

There are some fine moments of high campery: Flatley in bollock-hugging PVC pants, growling like Eartha Kitt. Flatley taking on Don Dorcha in a foot-slamming version of "Mars, the Bringer of War". And the company can dance so thumpingly well that they actually make the theatre vibrate, pounding a staccato beat that sounds like a symphony for Kalashnikovs. But these are joys under siege from the phoney awfulness of their context.

There's a word for it: Eiresatz, the cultural movement that produced Murphy's Bitter ads, Daniel O'Donnell and those Oirish pubs that have stripped Connemara of its roadsigns. These and Lord of the Dance are plastic paddyism at its most shiny, as pre- packaged as Marks & Spencer's potato salad. But no realities were going to spoil Thursday's fun in Manchester. With half the bombed city's centre still boarded up, Lord of the Dance had its head buried in the peat bog of pseudo-Celtic nostalgia.

Coliseum, WC2 (0171 632 8300), Tues-Sat, to 17 Aug; then touring.