On the busy shopping street in Giessen, a German university town twinned with Winchester, migrant Atif Zahoor tucks into a chicken dish with his brother and cousin at the curry restaurant Chillie To Go.

They have left good jobs back in Karachi, Pakistan, and now want to be Europeans.

In late July the three slipped into Germany with their wives and children, using illegal documents. They live together in a five-bedroom house, rented for them by Chancellor Angela Merkel’s government, a 40-minute drive away from Giessen, which is home to the biggest migrants’ camp in the country.

Scroll down for video

Migrants and refugees pictured waiting for a bus outside the Migrant Receiving Camp on the outskirts of the German city of Giessen. Social workers and women's groups warned that facilities were hopelessly inadequate and security was a problem for female residents

Migrants and refugees queue at the compound outside the Berlin Office of Health and Social Affairs as they wait for their registration. But there are warnings that millions more newcomers should be expected in the current migrant crisis

‘We paid a trafficking agent for false visas to fly here to Germany,’ says 34-year-old Atif. ‘We claimed asylum and came to Giessen camp with other migrants. Three weeks ago, because we had families, they gave us a proper home.’

Atif is well-dressed and speaks perfect English. He used to be a transport manager at Karachi airport and is from a well-to-do family. Between mouthfuls of curry, he adds: ‘But there is violence between political gangs in Karachi. Lots of people are leaving for Europe. The trafficker decided that Germany was the place for us because it is welcoming refugees.’

There is violence between political gangs in Karachi. Lots of people are leaving for Europe. Atif, 34, from Pakistan

Yet the raw truth is that Atif is not fleeing war or persecution. He is one of thousands of economic migrants getting into Germany as the EU’s immigration crisis grows bigger each day.

This week, David Cameron said Europe must send failed asylum claimants back to their own countries, while European Council president Donald Tusk has warned that millions more migrants are on their way and ‘the policy of open doors and windows’ must be scrapped.

They are tough words, but it’s action that is needed. As Jens Spahn, a deputy finance minister in Chancellor Merkel’s government, said this week: ‘Not everyone can stay in Germany, or in Europe. If people are coming for poverty reasons... we have to send them back.’

Mrs Merkel’s offer last month to accept all refugees from war-ravaged Syria opened the floodgates. More than a million migrants are expected this year alone, the bulk of them far from genuine asylum seekers. There is now deepening disquiet in this Christian country, dotted with churches, that it is being overwhelmed by people of a different religion and culture.

Refugees from Afghanistan and Pakistan inside a tent shared by more than 60 men at the refugee registration center for the German state of Hesse in Giessen, 40km southwest of Frankfurt

David Cameron said Europe must send failed asylum claimants back to their own countries, while European Council president Donald Tusk has warned that millions more migrants are on their way and ‘the policy of open doors and windows’ must be scrapped

Yesterday, the Mail reported how social workers and women’s groups in Giessen wrote a letter to the local state parliament claiming that rape and child abuse were rife in the refugee camp. The allegations were corroborated by Atif over his curry. ‘The camp is dangerous,’ he agreed. ‘Men of different nationalities fight and women are attacked.’

Many women have felt the need to sleep in their clothes... they won’t go to the toilet at night because rapes and assaults have taken place on their way to, or from, there. Letter written by social workers and women's groups in the Giessen camp

The letter says the camp, far from being a peaceful haven for those fleeing war, is a dangerous melting-pot, where there have been ‘numerous rapes and sexual assaults, and forced prostitution’.

There are even reports of children being raped and subjected to sexual assault, it adds.

‘Many women have felt the need to sleep in their clothes... they won’t go to the toilet at night because rapes and assaults have taken place on their way to, or from, there. Even in daylight, a walk through the camp is fraught with fear.’

Controversially, the letter suggests that in the migrants’ culture, women are viewed differently: ‘It is a fact that women and children are unprotected. This situation is opportune for those men who already regard women as their inferiors and treat unaccompanied women as “fair game”.’

Many migrant women have fled here to escape forced marriages or female genital mutilation, which are rife in some African and Middle Eastern countries. ‘They believe they have found safety in Germany,’ says the letter, ‘and realise it’s not the case.’

More breaking news on Europe's refugee crisis and the latest on Germany's migrant policy

Turkish volunteers living in Berlin give away water bottles and snacks to migrants and refugees queuing at the compound outside the Berlin Office of Health and Social Affairs

Locals in Giessen are appalled by the rape allegations. But many are also increasingly worried about the effect of the migrants — some 6,000 Syrians, Iraqis, Pakistanis, Kurds, Eritreans and others are housed in the camp, which was expanded last year — on their everyday lives.

Some complain that the migrants have taken over the town, which is famous for its botanical gardens and dotted with pretty boutiques and flower shops. You cannot miss the new arrivals, wandering the streets in large groups.

This situation is opportune for those men who already regard women as their inferiors and treat unaccompanied women as “fair game”. Letter written by social workers and women's groups in the Giessen camp

At the Lidl supermarket a few hundred yards from the camp, a well-dressed German woman packing her shopping into a Mercedes saloon rolls her eyes at me as a group of Middle Eastern youths walk by. ‘What do we do?’ she asks. ‘It has happened now and it will never be the same again.’

Some of the tales being told in Germany may just be xenophobic scaremongering. But there is no doubt that the country is grappling with a major culture clash as migrants pour in at the rate of 100 an hour or more.

At other camps among the 2,000 that have sprung up in Germany, I hear various lurid complaints about the arrivals, 80 per cent of whom are Muslim, single and male.

At a former U.S. military base housing some 2,000 migrants in Bayernkaserne, on the outskirts of Munich, women’s rights groups say there is forced prostitution and rape every day. Men, women and children sleep next to each other in tents and, according to one social worker interviewed on local TV, the camp is ‘the biggest brothel in the city’ where the price for sex with a female migrant is €10 (£7).

Migrants and refugees rest on beds at an improvised temporary shelter in a sports hall in Hanau, Germany, this week. EU border guard agency Frontex has warned a market in fake Syrian passports has sprung up, particularly in Turkey, to help migrants and refugees enter the EU

Refugees line up at a temporary shelter for asylum seekers in Giessen, western Germany. The United Nations is planning for the displacement of 500,000 people from the Iraqi city of Mosul if Iraqi forces launch an attempt to recapture it from Islamic State

The guards hired from a private company by the German government to provide security at the huge site were found by police to be trafficking drugs, guns and knives among the migrants as well as turning a blind eye to prostitution.

Yards from the camp, I talk to a Somali girl of 18, wearing a hijab. ‘We are scared some nights,’ she says solemnly, clutching her charity clothes in a white plastic bag.

They have their own culture. Because our school is directly next to where they are staying, modest clothing should be warn Letter to parents from Pocking grammar school

In other parts of the country, Germans are being told to adapt their lifestyles when migrants arrive.

Police in the Bavarian town of Mering, where a 16-year-old girl was reportedly raped this month, have warned parents not to allow their children outside unaccompanied.

Girls and women have been told not to walk home alone from the railway station because it is near a migrant centre where the rapist may live.

At Pocking, another well-kept Bavarian town, the headmaster of the grammar school wrote to parents telling them not to let their daughters wear skimpy clothing. This was to avoid ‘misunderstandings’ with 200 migrants who were put up in the school’s gymnasium over the summer, before being moved on this month.

The letter to parents said the migrants were ‘mainly Muslim, and speak Arabic. They have their own culture. Because our school is directly next to where they are staying, modest clothing should be warn... revealing tops or blouses, short skirts or miniskirts could lead to misunderstandings.’

Refugees and migrants wait at the compound outside the Berlin Office of Health and Social Affairs this week. A Berlin official today revealed they now think 30 per cent of those claiming to be from Syria are not telling the truth

Refugees queue at the compound outside the Berlin Office of Health and Social Affairs as they wait for their registration in Berlin this week. Germany has become Europe's top destination for asylum seekers

A 19-year-old waitress at a coffee bar in the town tells me: ‘We saw them [the migrants] walking around and they saw us. Of course, we were worried. We were told to be extra careful when they were here.’

A local politician, who refuses to be named, is quoted in Die Welt, one of the most respected German newspapers: ‘These Muslim teenage boys come from a culture where for women it is frowned upon to show naked skin.

These Muslim teenage boys come from a culture where for women it is frowned upon to show naked skin. Unnamed local politician

'They will follow girls and bother them without realising it is not acceptable. Naturally, their behaviour generates fear.’

At yet another migrant camp in Detmold, a city in central Germany, a 13-year-old Muslim girl was raped by a fellow migrant. The child and her mother had fled to Europe to escape a ‘culture of sexual violence’ in their own country.

Astonishingly, police kept silent about the rape, which took place in June. Only this month, after a local newspaper revealed that it had happened — and claimed German authorities are not ‘going public’ about crimes involving migrants because they don’t want to ‘give legitimacy’ to critics of mass migration — did they confirm it had taken place.

The area’s police chief, Bernd Flake, insists the official silence was meant to protect the rape victim. But he adds: ‘We will continue this policy (of not informing the public) whenever crimes are committed in migrant facilities.’

A young refugee waits at the rail station in Freilassing, southern Germany. The country now expects to welcome up to a million newcomers

Refugees rest in a former furniture factory after crossing the border from Austria in Freilassing, southern Germany. EU leaders have pledged at least 1 billion euros ($1.1 billion) for Syrian refugees in the Middle East

Meanwhile, the migrants keep arriving. Many have deliberately thrown away their passports on their journey through Europe, so they can pretend to be Syrian refugees rather than economic migrants.

The authorities, now being urged by both the EU and Germany’s leaders to return those who aren’t genuine, are completely overwhelmed.

At Freilassing, on the border with Austria, I see hundreds of migrants waiting in teeming rain to reach Mrs Merkel’s promised land. Wrapped in see-through charity macs, they queue excitedly for soup. Most have travelled for weeks, from Turkey by boat to Greece, then via Macedonia, Serbia and Croatia to Austria.

‘We are nearly there,’ says Arun Ari, 27, grinning. He comes from the Syrian town of Kobane, where Kurdish fighters have been battling Islamic State for two years.

He seems a deserving refugee among so many who are not, yet won’t show me his identity papers.

Deserving or not, he faces a tough future. Arun will be processed in one of the camps set up all over Germany in former military bases, school gymnasiums, sports halls, even a former monastery. Yet, just like him, almost every male migrant I meet is optimistic.

Outside the Bayernkaserne camp, for instance, I meet Ali, who arrived eight days ago via Greece. He used to be a travel agent in Lahore, the cultural capital of Pakistan.

The greater number of asylum seekers reaching Europe, many on flimsy dinghies crossing the Mediterranean or on hazardous journeys hidden in trucks, are from Syria or Iraq

Migrants and refugees line up as they wait to cross the border from Austria to Germany, near Freilassing. Chancellor Angela Merkel announced that Germany would admit all those fleeing Syria even if they had come via other EU countries

‘When I lost my job, I set out with six friends,’ he says. ‘There is every nation in the camp — a lot from Pakistan, like me. I chose Germany because they want us here.’

I dare not tell Ali this is not entirely true. Unless he is lucky, he won’t be given refugee status, as he is an economic migrant.

It is the same story when I meet Janaid Jamshad, a 25-year-old former student.

When I lost my job, I set out with six friends. There is every nation in the camp — a lot from Pakistan, like me. I chose Germany because they want us here. Ali, from Pakistan

Also from Lahore, he has been here for ten days. ‘I came to Germany first in 2013 and they pushed me out again,’ he says with a laugh. ‘I came back when I heard Mrs Merkel was opening the doors. I have claimed asylum and they are processing my application. Because I am young, I hope they will take me.’

Not that everything is rosy for him now. ‘The camp is overflowing,’ he says. ‘I have just been to the doctor in the shopping centre because I have a headache. Even there, there are queues of migrants waiting. The doctors at the camp will only give one pill at a time. So we find other places for medical help, and pay for it.’

Back in the Giessen curry house, I continue talking to asylum claimant Atif. ‘We think having children will help us,’ he says. ‘Our house is very big, and they give us money, too.’

I point out that Karachi, despite the political violence there, is not in a war zone.

He still hopes to persuade the authorities he is a genuine refugee, though, and hopes he won’t be returned to Pakistan because he now has no official national identity — in a deal with the smuggling gang, he handed them his own passport and those of his family when they arrived in Germany. They were the ‘payment’ in exchange for the family’s fake visas and will be used again to smuggle more customers into Europe.