The men are young, tall, lithe and mostly European, although today there are two Chinese. Most are impeccably dressed in pressed boot-cut black tuxedo trousers, carefully ironed white or black shirts and shiny patent-leather shoes. Occasionally, one of them will produce a large fan to cool himself with after a dance, like a peacock displaying for a mate. The women are all Chinese, middle-aged or older. Some are casually dressed in designer jeans and T-shirts, while others twirl about the dance floor in black taffeta skirts and sequined halter-neck tops.

Suddenly, the rumba of the Mambo Kings' Beautiful Maria of My Soul is replaced with a faster, Minnie the Moocher swing beat and several couples join the four already on their feet. At the back of the room, a man carefully guides his partner through her dance steps. But stealing the show is a woman, perhaps in her 50s and wearing tight blue jeans and a sleeveless grey top, moving in perfect harmony with her partner to the up-beat tempo. Their hips swivel like ball and socket joints, moving so close there is barely light visible between them, then away again until only their finger tips are touching.

Li Hua is well known as a place where Hong Kong's well-heeled dancers go to flaunt their skills. Here, the clothes on one's back or the diamond on one's finger isn't the measure of a woman's place in society; it's the rhythmic rapport they have with the expensive dance instructor on their arm.

Across the harbour, in Hunghom, a similar yet more grass-roots scene is unfolding. A banquet hall in Dance Cafe, above the UA cinema in Whampoa Garden, is buzzing with more than 100 people as they chat over tables of food, raising their voices to be heard above the taped music - foxtrots, tangos and waltzes. The venue is much brighter and more frenetic than its Causeway Bay counterpart, but the dancing is more structured and orderly. Couples follow standard ballroom steps gracefully and, despite the lack of room, there is little jostling. With a cover charge of $55, the punters are mostly retired couples and groups of friends, male and female. The attire is less flashy and there's not a Caucasian face in sight.

During its heyday in the 1960s and 70s, ballroom dancing was the domain of wealthy tai-tais, who were able to afford the high fees charged by overseas dance instructors and frequent trips to dancing hubs such as the English seaside towns of Blackpool and Bournemouth. Until recently, ballroom dancing had languished on the fringes of dance culture, an elitist sport for a privileged ageing few. But the past decade has seen it reborn in Hong Kong as an affordable dance-sport for a whole new generation. Television shows such as the BBC's Come Dancing, Australia's Strictly Dancing, America's Ballroom Challenge and reality-television show Ballroom Bootcamp, plus such films as Strictly Ballroom and Shall We Dance?, have reignited interest.

Dance studios, classes, clubs, salsa nights and a growing army of overseas instructors have arrived in the city. Established venues such as Western Market and clubs such as One-fifth, Post 97, the Edge, Jupiter and Tribeca have become mid-week hotspots for salsa, tango, cha-cha, meringue and rumba. No longer an elitist pastime of middle-class, middle-aged women, dance has been embraced by a younger crowd who'd rather work up a sweat on the dance floor with friends than on a treadmill at a gym. But devotees are polarised into two distinct groups: those prepared to pay for the pleasure of having a qualified instructor guide every move and those who are happy to shake their booty with the masses for a fraction of the price.

For those without the experience but with the disposable cash, the first tentative steps to a high-society afternoon tea dance begin in a place such as the Dansinn Dance Studios in Sheung Wan, where instructor Andrey Azarov, 33, is finishing up with a student. The studio measures about 3,000 sqft, has a bleached wooden floor and boasts mirrors along each wall. Lessons are conducted for individuals or groups, from beginner to competition level. In a room adjacent to the dance floor, piles of business cards read like an Eastern European telephone directory, while awards certificates and qualifications from academies and competitions across Europe adorn the walls, testifying to the instructors' credentials.

Dansinn caters to 'society' dancers - the Li Hua crowd - with world-class instructors who charge fees of about $600 an hour for a one-on-one lesson. With the right credentials, a top instructor from Europe or the United States can charge even more. In addition to lessons, their fee for an afternoon tea dance might be $1,500, with dinner dances at $2,000 and party performances from $5,000. That can add up to a monthly income of more than $60,000. For the few at the top of their profession, a retainer from a wealthy student can push that figure well over $100,000.

Azarov, a medal winner at the Alassio Italian Open Championships, was introduced to ballroom dancing by his parents at the age of six. The Russian says his parents loved to dance, even though it was frowned upon in the former Soviet republic. He arrived in Hong Kong with his wife and dancing partner, Eugenia, four years ago after a friend asked him to come and teach a client.

'There's a lot of demand in Hong Kong for dance instructors and we are getting a lot of new students, which is a sign interest is rising,' says Azarov, immaculately dressed in black tank-top, burgundy shirt, blue-and-gold tie and black flared trousers. 'There are usually about 30 western instructors in Hong Kong, but when there is a big dance competition in Europe, that number falls dramatically.'

For those wanting individual instruction without having to remortgage their apartment, there are alternatives. Sensing a burgeoning opportunity, visa-less teachers from the mainland have begun to infiltrate the market in Hong Kong, charging as little as $200 an hour. 'In the past few years, we have begun to see Chinese dancing stars and they'll soon be working [legally] in this market but, at the moment, they are concentrating on training for their own championships,' says Azarov. 'The studios here take only top professional dancers and teachers and it's hard to get a visa unless you are in that category. But some of the dancers from China are very good and they'll be working here in less than five years'.

For most overseas instructors, their Hong Kong career begins with an invitation to join a local dance studio, from where they build a reputation and list of clients. Students choose an instructor according to the style of dance they want to learn and how well they 'bond' with each other.

It was at a salsa evening in a five-star hotel four years ago that Loretta Fung met her dance instructor after she and some friends decided to take up a new hobby. The businesswoman was considering retirement and didn't want to join her contemporaries for long afternoons around the mahjong table.

'I didn't want to spend my retirement sitting down, so I went down to the Marriott hotel and a friend of mine introduced me to an instructor,' she says. 'I remember they were mostly from England, but also some from the US and Australia. I now go to lessons three or four times a week and have an instructor for ballroom and one for Latin. I'll probably go to Li Hua about twice a year, but there's always a dance party every month. If I didn't take my dance instructor, who would I dance with?'

Fung is reluctant to discuss how much her hobby costs, but it seems expense is not a huge consideration for this avid convert.

It's not only instructors who are cashing in on the ballroom-dancing boom. Sitting in her office surrounded by boxes of dance shoes, flouncy skirts and false eyelashes, Sandra Ng, general manager of dance-clothing retailer Iceco, says business is brisk. Dance outfits can cost from as little as a few hundred dollars to several thousand. Ng, who is also an instructor, says that while a few women like to have their costumes custom made, most are happy paying from $800 for a dress off the rack.

'A woman usually buys something slightly smaller than usual to accentuate her curves because she wants to look beautiful. You need to present a good shape so they wear it a little bit tighter,' she says. 'We sell a lot of black; it's boring but people like it because it's a slimming colour.

'When you are going to somewhere like Li Hua to dance, it can't be too formal. I wear something more casual. Competition is more colourful. People want to look sharp on the floor because it's a competition and there are a lot of couples out there. You want to stand out from the crowd.'

Ng's customers are overwhelmingly female, with work, golf and disinterest keeping men from the dance floor. 'The clothing we do is mostly for women,' says Ng. 'We would like to do more men's business, but there just aren't that many men dancing. I think they're too busy working and the ladies have more time and can afford to go to the tea dance. To be honest, the shoes and clothes are not very expensive; it's the lessons that are the most expensive thing, especially if you are going every day - and I know women who go every day.'

Men are certainly in the minority - three out of 20 - at the Thursday night beginners' class at the Fringe Club, in Central, as instructor Franky Wong puts the group through its paces. They've already learned four steps and a twirl, although some of the class seem to have introduced a few extra steps. A far cry from the moneyed Li Hua crowd, this group has forked out a reasonable $800 for eight lessons. Wong, 39, suggests affordability and the relative ease with which salsa can be learned is behind its appeal.

'[Standard] ballroom dancing like the waltz, tango, quickstep or foxtrot is a lot more technically demanding and it takes longer to get the taste of fun. With salsa, the restrictions and boundaries are less and you don't have to wait three years for enjoyment.

And [at] most salsa events, it's $150 for a drink and finger food and you spend 80 per cent of your time dancing. With ballroom, it's a table of 10 at $180 each, a big meal and you spend only 60 per cent of your time dancing.'

Economics, class, experience and wealth aside, Azarov says one simple motivation draws thousands of people to Hong Kong's dance floors, seven days a week, 52 weeks a year. It's one that helped his own parents survive for years under an oppressive regime and that paved the way for their son's successful career.

'People are really happy to dance,' he says. 'I see it in their eyes when I teach them.'