Our reporter was granted unprecedented access to one of Britain's oldest lap-dancing clubs. So how did she end up being turfed out in the early hours of the morning?

By around 10pm on a Wednesday evening, several women are undressing in the dank, cramped basement corridors outside the Windmill club's three windowless changing rooms. The combination of the unceasing rain and roadworks in the streets above is causing chaos. One of the rooms has flooded overnight and bits of the ceiling have fallen down. The other two are full already, so women are stripping off their clothes wherever there is space. Beneath the prevailing smell of hairspray and scent, a peculiar sewagey odour seeps in from Soho's flooded drains.

Women arrive in anoraks, wearing dirty trainers and fusty brown tights, eating greasy panini, holding their noses and complaining about the smell, and spend around an hour transforming themselves into beautiful, heavily made-up night peacocks, in floaty, gauzy, transparent dresses and leopardprint bras.

A lot of the women here this evening are Romanian and chat to each other in their own language, breaking into English only when they need help from the club's "house mother", a friendly woman from Northern Ireland who does their makeup. She looks younger than many of the dancers, but they call out "Mum" or "Mother" when they want her to apply fake eyelashes (which she supplies to them at £3 a pair), or if they need to buy a pair of tights or some new black lace knickers from the stock she keeps in a big red Family Circle biscuit tin. One of the club's two cooks comes in with a tray of assorted sandwiches for the dancers, which he sets down by a flask of coffee and a tower of battered red plastic mugs.

A new, shy-looking woman arrives with her sister, who's already a dancer here, to see if there is any chance of work. She hovers nervously for a while, until the club owner's son, Daniel, arrives to look at her in the changing room. It's not clear what the criteria are, but she passes the inspection.

"Yeah, she's lovely," he tells the house mother, glancing at the women in the corridor as they finish their preparations.

"Hello, my love. You should cover up these sandwiches, it's so damp here. Hello, gorgeous."

The women keep arriving until around 11pm, which is when the club's owner, Oscar Owide, likes the place to be packed with women.

"It smells like cat piss when you come in from outside," one woman says as she arrives.

"How was it?" another woman asks, greeting a dancer who has been away for a few weeks.

"Very painful."

"How are they?"

"A little bigger. But let's wait and see what the experts say."

"Well, at least you have had it done." Another dancer explains discreetly that she has had her PIP implants (the silicone implants found to contain industrial-grade chemicals) replaced with something less controversial.

Once they're ready, the women fold up their outside clothes, hand their phones and bags to the house mother for safekeeping, and make their way in spiky heels upstairs to the nightclub, where men pay £20 to see them take off their clothes again and perform what the club menu bills lasciviously as an "intimate dance".

Oscar Owide, the Windmill's owner, is himself something of a Soho institution. 'Silly women have said in the past that women are being exploited,' he says of clubs such as his. 'They’re not… They are young modern women who don’t find it difficult to undress.' Photograph: Linda Brownlee for the Guardian

Owide has agreed that the photographer and I can visit to try to build up a portrait of this Soho institution over 24 hours. We end up annoying him considerably and are vigorously turfed out, amid much swearing, on to the Soho streets sometime between midnight and 1am, the job unfinished.

On an earlier, less fractious visit, Owide had invited me to spend an hour in the club upstairs, to look at his lap-dancing business in operation and to talk about his love of Soho and the industry he's worked in all his life. It's very difficult to talk to him because he won't stay still for more than 30 seconds; every time he sits down, the conversation gets cut off abruptly when he hops up to say hello to new visitors, leaving me to look at the interesting way the huge disco ball throws pretty shimmers of pink light on to my notepad, so I don't have to look at the show on stage.

At 11pm there are customers at only four of the tables, and around 50 girls are at the bar.

"We need a minimum of 40–45 girls," Owide says, "so that he and his mates can have a choice, can have dances with different types of girls, whatever their fancies are."

The most peculiar thing about the place is the unusual contrast between the fully-dressed men and the near-naked women. One man is wearing a diamond golf jumper, another is in a Ralph Lauren polo shirt, but mostly they come in suits. The women wear underwear, some kind of Lycra, elasticky dress that doesn't cover the underwear, and nothing else. Most have hair that hangs long down their spines. The regulation hem level is a few centimetres lower than crotch level.

The woman who has been dancing around the pole on stage hobbles off, carrying the vest she had discarded during the dance. It would be an exaggeration to say she looks bad-tempered, but she doesn't look in a tremendously good mood. Her high heels are remarkable – transparent plastic, with maybe 4cm wedges at the front, flashing green lights with each tottering step.

"The dancers – they are all the same, but different. They are all individuals. They all have their own way of dancing. This is a good-looking girl," Owide says, approvingly, as a new dancer comes on to the stage. How does he define good-looking? "Lovely legs. Lovely figure. Lovely hair. They are all nice-looking girls. I don't think we have anyone who is nasty."

He looks at her and pops a few grapes into his mouth from the plate of fruit he has ordered. "We've got Polish, Czechs, Romanians, everybody here. All the eastern European countries." He unwraps a Chinese gooseberry from its papery leaves and eats it. "Eat one; it's good for you.

"I have one who has worked here 16 years… too long. But she is so lovely that she is not past her sell-by date. Most of them, they're here maybe eight years. It's fun working here. They get good pay. There are nice facilities."

A dead-faced, unsmiling, oldish man in glasses, with a greyish complexion and grey hair, sits down at a table with three women he's brought to the club with him. He's probably in his late 60s and the women are in their early 20s; he positions the youngest and prettiest of the three next to him and they hold hands underneath the table.

"Three! How come you got three?" Owide asks, warm and welcoming to the man, ignoring the women. Champagne is brought to the table.

The Windmill club is a former theatre and still has the stage and a small circle above the stalls. A staircase winds up the back of the stage, but leads nowhere. The back wall is covered with unusual silver glittery tiles and I ask what the technical term is for the material they are made from. "Glittery glitter, Owide says, amiably. "Black glittery glitter and white glittery glitter." The tables have big wine glass-shaped candles and notices advertising "fully nude dances in all private booths". The theatre seats upstairs have been removed and there are two rows of six little booths, separated by velvet drapes, with space for two people to sit. One bouncer stands with his back to the stage, monitoring what's going on in the circle; he looks bored.

Owide has been running the Windmill for 18 years, since he bought it off Paul Raymond. He says he's been working in Soho clubs for more than 50 years, but won't say how old he is. "You can ask, but I'm not going to tell you. I'm over 21. Have a grape." Before he came to Soho, he says, he ran a discotheque in Ilford. He has what newspapers refer to as a "colourful past", has been described in court as a "well-known Soho character", has in the past been banned from running a business, was once described as "Britain's biggest pimp" and served a prison sentence for VAT fraud. Cuttings suggest he is probably 81.

‘There are men with girlfriends, wives, kids, flirting with girls like me, asking you to have sex, spending all this crazy money… You get home and think, yuck.’ Photograph: Linda Brownlee for the Guardian

As more customers arrive, he looks around the room approvingly. "These are all nice people so far. Good people," he says. One man with a beard has two semi-dressed girls positioned symmetrically on either side of him, his head turning from side to side, as if he's in the crowd at Wimbledon, looking first at the cleavage to his left, next to his right. The man orders a bottle of vodka (£160). Owide explains that his description of customers as "good people" is not a comment on their morals, but really means people who are willing to sit and quietly spend money on alcohol and women. "Their behaviour is exceptional."

Throughout the evening, Owide carries on a cheerful, upbeat commentary. It's a relief to be able to tilt my face down and look at my notepad. "You can't call it their dream," he says, "but most girls, I think they feel they would like to get up on the stage and dance like this once in a lifetime. They enjoy the fun of it."

He works hard at highlighting the innocent fun being had here by customers and dancers alike; he likes to see the club in the vein of Carry On films or saucy seaside postcards – "rude and naughty, but not dirty". He has a wrinkled, old-fashioned voice from the 1950s, which, fittingly, has an ooh-matron ring of Kenneth Williams or Terry Scott.

I'm not laughing much at his jokes and must be looking rather boot-faced, which begins to make him irritated. I'm asking about staff pay and alcohol prices, and I sense he is getting fed up with having me around. "You're asking about the business. You need to understand the humour of it," he says. "You should have worked here for the night. That's the best way to understand it." I'm stuck as to how to respond.

Only later does Owide finally say something that makes me laugh. He turns to a colleague and says with delight: "She has got a sense of humour! When she sat here – she wouldn't smile. I was thinking of doing something like exposing myself, but nothing would have made any difference."

"Would you like a dance?" Owide Jr asks, pointing up to the balcony. "You don't want to experience a dance?" Girls are leading men by the hand upstairs. One woman stands up next to her companion and her top accidentally falls off. She slowly ties it back on.

The Windmill has open auditions every day of the week. "We're always looking for lovely people," Owide says. He keeps using the words "lovely", "fun" and "nice".

He brings over Laura, who's 26 and has been working here for about five years. She's smiley and friendly, in a proficient but hollow customer services way, and keeps pulling at her skirt, which is hovering at the top of her spray-tanned thighs, as if she's uncomfortable talking to a woman who's got clothes on. She alternates this job with lifeguard shifts at a swimming pool, and she doesn't describe it as fun; her most positive assessment is, "It's not so bad, to be honest.

"I'd never done it before. When I first came, I was a bit shell-shocked at girls taking their clothes off. But after a while, they were so nice, the boss is so nice. It helps having a nice boss to give you courage," she says, glancing in Owide's direction. "I knew how to dance. It was just getting past that stage fright, taking the clothes off."

She explains that there is no base salary and that dancers pay a daily fee of £60 to the club for the right to work there. "If you are sitting at a table, you get paid. [Men] buy a girl for £100 an hour, or an hour with all the dances included for £140," she says, adding that tonight has been a slow night. "I haven't made anything yet."

She says she has never had any bad experiences in five years, conceding only: "It gets tiring wearing heels all night. It does get tiring. My mum says, if you've got the body, go for it. My dad… He's not really bothered. It's not a job he would want his daughter to have, but it's a job."

Does she like the men who come here? "You get a lot of accountants. Just ordinary men. Normally it's stag parties." Momentarily dropping her cheerful front, she adds: "You get to know what men are really like, doing this job. It makes you a lot wiser. I can't put it into words." Then she gets up to leave, smiling again. "I'm going to go off now and make some money."

Daniel Owide comes over to advise me to go to the front of the stage and look up to where the bouncers are looking. "Look from this angle. You'll get another perspective."

In each of the six booths upstairs there's a man in a suit pressed into the back of his chair, sitting bolt upright; in each there's a naked woman, writhing and shaking her flesh in his face.

I stand there for a while, awkward with my notepad, until Oscar Owide says the customers are uneasy at my standing taking notes and I'm banished downstairs.

In his crowded office in the basement, cluttered with pictures of dancers, old Christmas decorations, willy-shaped straws and cough mixture, Owide continues his defence of the lap-dancing industry. "A lot of women think the girls are being exploited, and then, when they come to a club night, they realise it is the other way round, that the guys are being exploited. They realise it is a fun thing to do, it's not slavery, nobody is making anybody do anything they don't want to do. The girls working at this establishment – I can't speak for everywhere – enjoy coming to work. They enjoy making themselves look pretty every evening.

"Silly articles have said…" He pauses and gives me a hard look. "Silly women have said in the past that women are being exploited. They're not being exploited. You're not talking about the suffragette years. They are young modern women who don't find it difficult to undress."

He is right that there has been a shift in attitudes towards these clubs. Over the first decade of this century, there was a huge expansion in the number of lap-dancing clubs, until licensing laws were tightened in 2010. Campaign groups, such as Object, say that regulation shift came too late; by that point clubs had become mainstream, and people began to view them as "harmless fun", normalised to the extent that customers viewed buying a lap dance as no worse than buying a cappuccino. These clubs "reinforce the idea that women are always sexually available, as long as you've got a bit of cash to spare", Object argues. The "clubs reinforce sexist attitudes, are linked to sexual harassment in and out of them, and run counter to efforts to promote gender equality".

Owide has other concerns. He is worried about money, and you get the sense that times are not very good for the industry. "We're not recession-proof." he says. "Life is more difficult for everyone."

The women here do not receive any training. "They're not advised as to what they should be talking about, they're just advised about how they've got to behave. They've got to be nice people. Guys want nice conversation."

What does nice mean? "People don't want to be offended. You want someone to have a lovely conversation with you, not talk about your dead grandma. That sort of conversation.

"What do guys talk about? I don't know. They talk about themselves and their sexual desires, how much money they have… and how much they're going to give you."

Summing up the club's appeal earlier, he said it gives men the chance to look at girls "far prettier than they would ever be able to marry, in front of them with their legs wide open. It's amazing." Prostitution is not allowed; women get no training in how to handle the frequent requests for paid sex.

"If a guy asks her for sex, she'll say no. That happens all the time, everywhere. They don't have to be trained… They just don't have sex. It's as simple as that." Clients are not removed for propositioning dancers. "No! Why should we chuck the client out for asking one of the most basic questions in life – 'Can I give you one?'" He blasts out a croaky laugh.

He is a bit vague, as everyone is, about how much money women here earn. It's peculiar how imprecise is everyone's assessment of earnings.

"It's very difficult to define, but a man who enjoys himself enormously will give a girl £50 or £60 or £70 a dance; there's a minimum price of £20 a dance. Then you go on to a guy who will sit with a girl for an evening and maybe pay £500 or £600. There's a £100 an hour fee at the table. That goes to the girl. It's entirely her money, although there's a house fee to pay."

Who are the customers? "Everybody, whatever walk of life, from 28 to 78. Older than that, much older. We've got customers in their 80s who I've known for 50 years. We've had a 90th birthday celebration here. His grandchildren brought him."

Owide takes great pride in this being a family business and points out that his son has 25 years' experience in running clubs, but he admits he doesn't want his grandchildren to join him. "I won't allow the grandchildren in. Not in my business. They're all doing more professional things. They will have a different kind of life."

As they get ready to go to work, the women don't give the impression that their job is fun. They enjoy chatting to each other as they get ready, but they don't talk with great enthusiasm about their encounters with the club's clients. They don't complain that they're being exploited, but they are frank about the difficulties of working here. A minority may be making money, but several who say the money is OK are using exceptionally low benchmarks. For the Romanian women, visa restrictions mean it's very hard to get other work. Aside from Laura, I don't meet anyone who's told her parents how she earns her living.

Maria, 25, from Romania, likes working here because the pay is better than the sub-national minimum wage she got in cash when she worked in a pub in Wembley. She was paid £176 a week for working a nine-hour day, six days a week.

She is a bit vague about how much she earns now. She claims – as do several other women – that it's possible to make £1,000 a night here, but she admits it doesn't happen very often. "It is the recession now. I've noticed that a lot. There are fewer people and people are not as generous, not as eager to pay as much as they used to."

Does it make you rich? "Me personally? I wouldn't say," she says, fastening on false hair extensions. "Some girls have been very smart with their money. Other girls support a lot of people and are sending money home. It depends on what other responsibilities you have."

Her boyfriend is a builder and they find the cost of living in London exorbitant. "We rent the room in Wembley for £500. It is very expensive."

She hasn't told anyone about her job. "I can't tell my dad. I think he would call me a prostitute."

Behind her head there's a photocopied dress code, with suggestions for appropriate, skimpy clothes. Most of the outfits the women have on are considerably skimpier than those shown. There's also a printed sign, warning: "Any girls taking money on the promise of sex will be immediately dismissed and all clubs will be given a copy of her passport."

"Before I started doing it," Maria says, "I didn't think it was respectable. I was sceptical about the girls that work here. I thought doing this and being a prostitute was the same thing. But I needed the money."

Jennifer Hayashi Danns, who worked for two years as a lap-dancer when she was a student and last year co-wrote Stripped: The Bare Reality Of Lap Dancing, with Sandrine Lévêque, says that, in her experience, few dancers are straightforward about their earnings. "There is successful propaganda that you can make a lot of money from it. The economic model is based on having the maximum possible number of women in the club. The more women in there, the greater the selection for the men, and that's how they make money," she says, referring to the house fees women pay in all clubs. "It's just win-win for the club, but not so good for the women. When you work as a lap-dancer, you aren't paid a steady wage. It's an extremely humiliating thing to admit to another person that you aren't making much money. It means that no one wants to see you naked. I don't know anybody who is honest about what they are earning."

She points out it's hard for women to be anything but positive about their work while they are still doing it. "People say they feel more empowered, but do their parents know? No? Well, that's not really empowered, if there's this big secret."

Beata, from Poland, who has been studying towards a tourism degree, laughs and says she hasn't told family or friends. "No! No one knows. None of my friends. Come on! It is a shame… I think so. Then they think you are a prostitute or something. I once met a girl who was doing the same job. I used to think she must be a prostitute."

The women say they don't think there's much prostitution on the sidelines of the club. "If any of the girls do that, it would be a minority because you earn so much money here anyway," one says.

Beata isn't clear about how much she earns. "Honey, you never know. One night you can make zero, the next night 1,000." Regardless of the pay, it's a hard job to do: "We have to get shit naked in front of guys we don't know." She is saving to buy a flat in Poland and isn't certain how long it will take her. "I'll do it for another four years. No longer. Then I want to have kids and a husband."

Linda Brownlee, Weekend's photographer, has been given permission to take pictures of the women as they get ready, and at the last minute I join her. My presence hasn't been cleared this evening with Oscar Owide, although I say hello to his son, who says I should let him know if there's anything he can do to help.

But Owide Sr is in a furious temper when he arrives and stamps downstairs, shouting at people. "Can someone get these fucking umbrellas out of the way." He isn't pleased to see me. "How long have you been here?" I say I'm waiting for Linda to finish and he disappears to do something else.

A Spanish dancer, who recently graduated from a good London university, has been working here for a year to pay off student loans; according to the house mother, she appears to be earning more than some of the other women. She says the work is empowering, and better paid than the entry-level jobs she could have applied for on graduating. "I want to have my independence, my money, not be relying on anyone else.

"I thought it was hard the first week. I don't find it weird any more to be running around naked up there," she says. She spends a lot of her time disguising from the clients how well-educated she is. "Most men don't like to see that the girls are cleverer, or to feel they are at a disadvantage. They think, oh no, you're too clever for me, you're going to run off with my money."

She concedes, though, that she finds the work emotionally exhausting. "You get tired with waitressing and tutoring, but this is psychologically so tiring. You get home and you think, yuck. You have to be in a good mood, entertaining, smiling all the time. You're the one making the effort. They don't make an effort; they're paying.

"I never really gave men much credit anyway. There are men with girlfriends, wives or kids, flirting with girls like me, asking you to have sex, spending all this crazy money. I don't think their morals are very good. I'll do it until I'm 25, max."

A cheerful 24-year-old ex-au pair from Italy begins, like all the women, with an upbeat account of why she likes her job, but her breezy enthusiasm begins to drain away when she focuses on the details. "It is fun. It's like clubbing every night. I don't have a lot of plans. Just to save enough for travel." As an au pair she earned £150 a week; now she earns more (but she can't say how much).

"Before I started, I thought it was going to be worse. That it was going to be horrible people. It's not so bad. One guy pulled my hair once; when guys are drunk, they try to touch and talk dirty. But you manage. You get used to it. Sometimes the older ones, they are a bit disgusting, talking trash. You just smile and say, 'Yes, right.'"

She hasn't told her parents. "Do you have children? Would you like your children to do that? Do you make children for men to look at them naked? Imagine your kids being looked at by men… When you are a kid, you don't say, 'Aah, I want to be a stripper when I grow up.' I wanted to be a writer. I enjoyed working in a pub, but I was paid £6 an hour. I was working really hard for nothing.

"It is cold up there. They put the air conditioning on. You aren't allowed to put your clothes on. You have to pretend you are so interested in these guys who are telling you bullshit," she says, adding firmly, "It is not the worst job in the world."

A couple of women come down and ask the house mother to unlock the dressing room so they can get something out of the lockers. "Mother, I just want to get my lip gloss. My lips are so dry."

They call you Mother? "I know. I hate it," she says and laughs. Later in the evening, once she's helped with all the makeup, she is there to chat to the dancers when they come down for a break. Part of her job, as she sees it, is to cheer them up when men have been mean to them, or if they haven't made any money, which naturally is taken as a brutal assessment of their attractiveness.

"Some of the girls shouldn't be doing it because they don't make money," the house mother says. "You have to have a thick skin and the right kind of mentality. Some customers might not like them. You have to be able to take it on the chin. If they get knocked back, I am here to console them. Some of them who are starting out, they do take it personally. They get their feelings hurt if they ask a customer if he wants a dance and he doesn't."

The most frank woman I speak to is a bit older than the others, and comes down to rest her feet while they're upstairs. She is wearing a 1950s-style blue waitressing outfit and looks tired and sad. She tilts her head against the wall and says she wants to sleep; she has been doing the job for five years.

It's midnight and she hasn't earned anything yet. "You have good days and bad days. There are too many girls; there are only a few men. If there are too many girls, it is a waste of time. You pay the money whether or not you earn anything. You feel the time going so slowly. If you don't make money, you get so angry." She sounds depressed.

Owide comes in and is cross to find we're still in the club, talking to his staff unsupervised. His amiable demeanour has evaporated. There is an explosion of swearing; one of the dancers rolls her eyes behind his back, as if she's heard it before. We are escorted from the building. "No one talks to the girls like that. No one," he says "I'll phone the editor and have the piece stopped."

All the women's names have been changed and some details altered to protect their identities.