It is nearly 11pm as snow falls on the narrow streets of Amsterdam.

Two young men wearing hoodies swagger up to one of the full-length windows in the most famous sex district in the world.

Bathed in eerie red light are three women wearing only lace underwear. One plays nonchalantly with her phone, not bothering to look up at the men leering at her.

Another applies her lipstick. A third sways gently from side to side, staring out with a fixed smile.

Bathed in eerie red light are three women wearing only lace underwear. One plays nonchalantly with her phone, not bothering to look up at the men leering at her

The men are probably British. They come here in their droves, on holiday or for stag weekends, to gawp through the windows of the city’s brothels.

Some respond to the women beckoning them, no doubt emboldened by the fact this is De Wallen, where prostitution is not only tolerated but is perfectly legal, and where credit cards are accepted by the notorious ‘window women’.

Tricks are turned with astonishing speed and the women can earn up to £350 on a busy day.

Perhaps that is partly why the myth of the happy hooker has been allowed to flourish in these seedy streets.

But the reality, as The Mail on Sunday discovered, is far more grim, sordid and dangerous.

Scores of human trafficking trials in the Dutch courts have exposed the horrific truth – that many of the smiling window girls have been brought from Eastern Europe by ruthless pimps who think nothing of handing out a beating, a knifing or rape.

One young woman who had been forced to Amsterdam revealed to The Mail on Sunday: ‘We are being sold just like something in a shop.’

The reality, as The Mail on Sunday discovered, is far more grim, sordid and dangerous. Pictured: Amsterdam's red light district

Spurred on by horrific tales of women suffering coerced cosmetic surgery and forced abortions, a growing number of politicians and campaigners in Holland have turned against the sex trade.

The new outlook is summed up by a Dutch MP, who told the MoS that the brothels – seen by so many as just good dirty fun – are nothing more than ‘commercialised rape’.

Now a new law, likely to come into force next year, will make it an offence, punishable by up to four years in jail, for punters to have sex with a prostitute they know – or suspect – has been trafficked.

In the words of the international campaign challenging sexual harassment and the exploitation of women, could it finally be Time’s Up for Amsterdam’s red light district?

That time cannot come fast enough for Angelica, a Romanian who spent five nightmarish years as a captive in the Amsterdam windows.

One young woman who had been forced to Amsterdam revealed to The Mail on Sunday: ‘We are being sold just like something in a shop’

She tells us her chilling story – about the transformation of a bright, ambitious teenage student into a broken woman, aged just 22.

As a 17-year-old she was lured to London by a man she thought of as a boyfriend, having been told she would get a well-paid job as a hair stylist.

Unknown to her, at the other end of the easyJet flight was a willing customer, but he hadn’t paid for a haircut – it was Angelica he wanted.

Her passport was taken away and she was effectively taken prisoner. Soon she was ‘sold on’ and installed behind a grubby window of an Amsterdam brothel.

‘The man who brought me to England and then to Holland used me like a piece of meat,’ she says.

‘When I saw the brothels with all the girls in the windows, I cried. I cried very hard because they looked horrible, and I knew that was what was coming to me.’

She was told she owed £27,000 to the traffickers because they falsely said her family had been paid off not to report her disappearance.

Her £350 daily earnings went straight to the brutal pimp who gave her just £9 for food. He also raped and beat her.

Despite the horrific reality exposed by Angelica’s story, the men in the red light district do not seem to care if the women have been trafficked

Clients were charged £35 for straight sex – or £90 without a condom. Angelica was cut on the face with a knife by her captors when she tried to refuse a client’s demand to have unprotected sex, and she was threatened with much worse if it happened again.

Little by little, the message got through that her body now belonged to someone else.

She adds: ‘Pimps would tell me it’s legal, that they can do what they want to me because the police are on their side and not mine.’

Of her clients, she says: ‘The English are the worst. They treat me like dirt. One even urinated all over me and laughed while he was doing it. They are always drunk. They hurt me.’

Her phone was taken away and she was given a basic Nokia with a few pounds’ credit so that she could keep in touch with her pimp.

Angelica worked 12-hour shifts, sometimes sleeping in her brothel in case a punter wanted sex early the next morning.

Eventually one of the support agencies whose staff tour the area came round and on their 12th visit she told them she had been trafficked and wanted to escape.

Next, a plain-clothes policeman arrived posing as a client and she spilled out her story.

Finally, police took her to a refuge outside the city. But her time in the windows had left a grim legacy.

She had contracted a venereal disease, was forced into an abortion, and for a long time her family refused to speak to her – convinced by the traffickers she had entered prostitution willingly.

One of the British tourists we spoke to says: ‘I assumed one woman was trafficked because of the way it was set up with a big guy standing outside'

Now back in Romania, living in a hostel and in touch with her family, Angelica says: ‘I now understand I was trafficked, but then I didn’t even know the word.

'The problem is that once I was in that brothel, everybody just walked past smiling and waving, or glaring and laughing, including some of the police, because everything was perfectly legal.’

Despite the horrific reality exposed by Angelica’s story, the men in the red light district do not seem to care if the women have been trafficked.

One of the British tourists we spoke to says: ‘I assumed one woman was trafficked because of the way it was set up with a big guy standing outside.

'The woman looked younger than 16 and appeared to be Polish, Russian, Albanian or Romanian.’

Another says: ‘One of the women in a window had bruises and cuts. I asked her if she was OK and she just smiled and said she was.’

A third shrugs and says: ‘They all want it don’t they, if it’s legal? If it’s behind the window and it’s obvious and blatant and in your face, that means it’s not underground, it’s not illegal, and they want it.’

Stories like Angelica’s have swayed public opinion in Holland and today thousands of protesters are expected to march in The Hague – home of The Netherlands’ government – to demand that the country’s brothels, legalised in 2000, are again outlawed

But stories like Angelica’s have swayed public opinion in Holland and today thousands of protesters are expected to march in The Hague – home of The Netherlands’ government – to demand that the country’s brothels, legalised in 2000, are again outlawed.

Renate Van Der Zee, a long-time campaigner against the sex trade in Holland, has found that her cause, once regarded as controversial, has now gathered mainstream support.

‘I realised that legalisation didn’t change anything in prostitution,’ she says. ‘The whole Dutch system was set up by wishful thinking. Women are not safe under legalisation.

'There is a movement across the world now to end the sexual exploitation of women. We’ve seen this with the Time’s Up and #MeToo campaigns.’

Dutch MP Gert-Jan Segers, leader of the Christian Union party in the coalition government, says: ‘We legalised prostitution in 2000.

On the march: Women making their feelings known

The idea was it was giving women their freedom and to get rid of the criminality. But we took it away from being linked to freedom and we linked it to human trafficking.

‘The red light district is a dark place. It’s chilling, it’s humiliating – it makes me cry.

‘For a long time we just accepted it – there are tour guides telling naughty and funny stories about the place. But the reality is that it’s just commercialised rape.’

As well as increasing the minimum age of prostitutes from 18 to 21, the legislation could make men far more wary about paying for sex. ‘We are making the buyers responsible,’ says Mr Segers.

‘They should be prosecuted if they know or could have known that they are making use of a victim of forced prostitution.

‘From a human rights perspective, De Wallen is a terrible place. I hope that this law will be a clear warning that if you cross that line you will be prosecuted, including tourists.’

Jolanda Boer, a senior public prosecutor specialising in human trafficking, says: ‘The British tourists see the red light district as a circus, but they should keep in mind that these girls might not stand there voluntarily and they are exploited.’

Jackie, 42, a prostitute who works for Proud – an advocacy group for sex workers, says: ‘At the weekends we’re packed with British tourists – they’re so loud and rowdy.

They think anything goes in this area, but it doesn’t. It’s like an erotic Disney World, but people also live and work here.’

Hala Naoum Nehme, a former volunteer support worker for the De Wallen prostitutes, adds: ‘We should be ashamed at how we are treating the women behind the glass.

'I would ask everyone who has romantic ideas about the red light district – are you sure those women are not being forced?’

Meanwhile in Britain, the Amsterdam model has been held in such high esteem that in 2014 the first – and only – legalised red light area was given the go-ahead in the inner-city Holbeck area of Leeds.

Similar ‘tolerance zones’ have been proposed in other cities.

The number of sex assaults have increased dramatically in Holbeck since it was legalised as a red light district where kerb crawlers do not face arrest, but advocates of the scheme say this is because women feel safer to report crimes.

Mary Honeyball, a Labour MEP and vice-chair of the women’s committee, believes the experiment was ‘doomed from the start’.

She says: ‘It does these women a huge disservice to think that by sending them into a so called “managed zone” they are safe.

‘If anything, they are even more vulnerable because by giving them a designated area it risks normalising prostitution and everything that comes with it.’

Perhaps the last word should go to Fiona Broadfoot, a former Leeds prostitute, who says: ‘This so-called safe zone is not safe. The act of prostitution is not safe.'