The huddled masses besieging Fortress Calais

Thousands of people are living in makeshift camps in Calais hoping that one day they will make it to the UK. Many once had good jobs - but fleeing from war and persecution most now have no money, and little dignity, in a town that is fed up with them.

"Life in Calais? It's close to animal life. From early morning you're just thinking about food and then, to sleep again.

"You start thinking about basic needs - to take a shower, to take a shave, to cut your hair. And you're just close to animal life."

The speaker is Osman - a gentle, well-educated Sudanese man in his late 20s. He's quietly explaining how his life has been shattered.

"I don't know what to say, I think I lost everything. I am just now on empty. An empty guy, I don't have a plan, I don't know where to go."

It had all started two months earlier, after he was arrested and tortured by the regime in Khartoum for organising political opposition meetings.

Foolishly he'd invited other political activists to his home and a neighbour - a government loyalist - had told the secret police.

After discharging himself from hospital, where he was being treated for injuries sustained during an interrogation, Osman's friends got him a place on a cargo ship heading for France.

He arrived there with nothing and was advised by people he met to head to Calais, and then on to the UK. Getting to the UK, he was told, was the best option for an English-speaker seeking asylum in Europe.

So here he is, living a feral life in a sprawling squatter camp on the outskirts of Calais.

Osman is not alone. There are thousands of migrants here now. No-one's quite sure how many - 2,000 or 3,000 perhaps.

The numbers are growing daily and all have their hearts set on a new life in the UK, which they appear to believe is a kind of wonderland that will answer all their problems.

But the UK border is closed. The frontier has been physically moved to inside the port of Calais - and what a border it is.

Triple-layer, chain-link fences standing 20ft (6m) high with coils of razor wire running along the top. Security guards, sniffer dogs, electronic heartbeat detectors, squads of heavily-armed CRS riot police, banks of CCTV.

The port of Calais now looks like a throwback to the Cold War - not a border town demarcation between two rich friendly nations which haven't fought each other for 200 years.

I remember visiting this place years ago, first as a schoolboy on a day-trip with my French language class, and later on "booze cruises" to buy cheap French wine at vast discount warehouses. Back then Calais was just a normal-looking, slightly dull provincial French town.

Now the port is a fortress and the migrants are ever-present, living rough on the streets, in squats and in vast, filthy campsites they've nicknamed "jungles".

These intimidating, lawless places are like a kind of United Nations of human misery, with representatives from every major conflict - I meet Afghans, Sudanese, Iraqis, Syrians, Libyans, Eritreans, Pakistanis, Iranians… the list goes on.

And here, on the windswept coasts of northern France, they are daily being stripped of their dignity.

Most are penniless, having already paid human trafficking gangs to smuggle them into the EU in the first place.

Now they try to stow away in, or underneath, the thousands of heavy trucks that trundle through Calais on their way to the ferries which take them across the narrow English Channel to the UK.

It's a risky game. Dozens of migrants have been killed and hundreds seriously injured falling beneath the wheels of these enormous vehicles.

You can see them gathering every night - in groups of 10 or 20 - dressed in dark clothing, hooded and wrapped up against the cold.

Sinister and wraithlike, they hover around petrol stations and lorry parks looking for an opportunity to sneak on board parked or slow-moving lorries - all the while trying to avoid patrols of the feared CRS riot police.

But the roots of the problem lie far away from this small French port town, and nothing done about it here can be more than a sticking plaster.

"It's very easy to say you should put fences everywhere along the port, around the port and have more police forces," Deputy Mayor Philippe Mignonet tells me.

"You can have thousands of kilometres of fences. You can put fences up to Madrid, Berlin, Vladivostok. That won't change the fact that those people are leaving their countries."

People like Mustafa, a statistician from Aleppo in Syria. He fled the shell-shattered city with his 10-year-old son Izeddine, spending his life savings to get from Syria to Turkey, then on to Algeria by sea, then through the desert to Libya, then across the Mediterranean - for a second time - and overland from Italy to Calais.

And here they are, 33 kilometres (20 miles) from a goal whose proximity both tantalises and torments them.

"There is many reasons for I choose UK - the important one for language," Mustafa tells me in broken English.

Then he reels out a list of reasons why Britain is the best place - the only place - that can provide him and his family with salvation.

I met Mustafa and Izeddine on the long, sandy beach outside Calais port. Izeddine is playing with a kite, but Mustafa admits that he didn't bring his son down to the water for fun.

"There are no showers where we stay," he tells me. "We have actually come down here to wash ourselves in the sea."

This is not the first time Calais has experienced a surge of migrants, although it is by far the biggest, the deputy mayor says.

The recent collapse of state authority in Libya has turned that country into a massive human trafficking staging post for people desperate to escape the extreme violence in Iraq, Syria, Afghanistan and Sudan and to flee lives of long military service and repression in Eritrea.

In the past refugees flocked here from other wars - Iraq and Afghanistan again, and the Balkans.

While I am interviewing one local official a man drives past on a motorbike and yells in French: "We are sick to death of Les Kosos."

"It's the local Calais slang for migrants," I am told. "We call them that because originally - years ago - they all came from Kosovo."

In the late 1990s, a Red Cross camp for about 900 refugees was opened at the nearby village of Sangatte, on a site that once housed the enormous drilling machines used to dig the channel tunnel.

But it was closed three years later after the migrant population soared to more than 2,000. It had become both a magnet for new arrivals and a criminalised trafficking centre for onward movement to the UK.

The Sangatte Red Cross refugee camp in December 2002, ready to be dismantled

Wary of building any new facilities that might be seen to "encourage" more migrants, the British and French authorities have adopted what charities describe as a policy of "deliberate neglect".

Currently neither state provides shelter, accommodation, food or medical care - apparently in the vain hope that word of the deprivation and primitive conditions will somehow filter back to the world's war zones and refugees will decide to go somewhere else instead.

If that is the plan, it's not working, and it has fallen to local humanitarian charities to offer a modicum of welfare and assistance.

Every day at 18:00 local time, hundreds of migrants gather in long, snaking queues in a car park in central Calais for a free meal.

It's a bizarre, almost Biblical scene, with legions of ragged men - and they are nearly all young men - shuffling quietly forwards across the dusty ground to receive what for many of them will be the only thing they eat all day.

And when they sit down on the ground to eat, the place becomes a Babel of the world's tongues - Tajik, Pashto, Arabic, Dari, Tigrigna.

But although they are all in the same metaphorical boat, the migrant communities do not always get along. There have been fist-fights and even mini-riots, so the feeding station is constantly monitored by squads of armed French police.

Crimes committed by migrants against the local population are also rising.

"Crime has exploded in the last three months. Violence, theft, rape attempts - it exists and it goes up. Theft from vehicles, from shops," says a police union spokesman.

"When they walk around town in groups of 10 or 20 in the evening, if you come across them when you are alone with your kids, of course you don't feel safe at all."

Everybody is fed up, says Mr Mignonet, the deputy mayor - the police, the hauliers, the port security, the citizens and the migrants themselves.

"Everything is explosive now," he says.

"We know if nothing changes rapidly, we will face major problems.

"Everybody in Calais now has got the feeling that nothing is done by the rest of Europe… no decision is taken anywhere."

It is no surprise that right-wing nationalists have formed a direct-action group, Sauvons Calais - or Let's Save Calais.

The group's twenty-something members are described by opponents as thugs, but the views they admit to in public don't differ much from those of many ordinary people in Calais.

"This is a European problem, because the Schengen Agreement [enabling passport-free movement between a large number of European countries] has made Europe's borders sieve-like.

"It is also because of the Le Touquet Treaty that put the English border in Calais, blocking the migrants here," says the group's founder, Kevin Reche.

"The solution at the international level would be to renegotiate these treaties.

"The other solution is simple. Expulsion - deport all those you can. I think an Afghan would be much happier back in his own country than here in Calais."

Everyone is on edge, says Calais Police's Gilles Debove.

"Our mission is to get the migrants off the trucks - when it goes well, that's us done. There are even times when it makes us laugh and them too," he says.

"But the problem is that it is becoming tense now. On both sides, we are fed up of this cat-and-mouse game. Nothing's changing. I feel that it is really heating up. Watch out."

He isn't joking. One morning I see a seemingly innocuous incident spiral out of control. A migrant falls off a lorry he has been trying to board and is rushed to hospital.

But a rumour goes around that this man was assaulted by the police - and suddenly hundreds of migrants pour onto the motorway near the port, attacking lorries and throwing missiles at police.

For several hours running battles continue up and down the dual carriageway.

It is a bizarre sight. An army of furious, ragged young men bodily hurl themselves at security fences and are repelled by heavily-armed, masked riot police officers - while in the background cars carrying tourists with crates of cheap wine, and lorry drivers with their cargoes of consumer goods trundle past.

It feels as though the realities of the rest of the world are slowly encroaching on a Western European daydream.

In his squat, Osman borrows my smartphone. He opens up his Facebook page - the profile picture shows him standing in front of a massive, futuristic looking wall of neon advertising somewhere in Tokyo. It was taken while he was visiting Japan last year on a business trip.

What, I wonder, would last year's Osman make of the husk of himself standing before me now?

"You were an engineer?" I ask.

"Yes, I was an engineer. I was a process engineer, a design engineer. One time I was even a project engineer." There's a small, proud half-smile, then it vanishes.

"Your life took a really strange turn, Osman," I say.

"Yes," he replies mournfully. "I became like a Tarzan or something."

All the clothes Osman owns he is wearing, he tells me. "When I need to wash them I have to do them one by one."

Tents are set up inside a sports centre in Calais

So many of the desperate people I met in Calais had once lived lives of predictable normality - until one day they found themselves under threat and on the move, illegal and unwanted.

Mustafa the statistician from Aleppo, on the road with his 10-year-old son Izeddine. Ahmad, a video editor from Kabul. Hussein, an English teacher from southern Iran. And Osman, the engineer from Khartoum.

They know what it is like when the roadblocks go up, when the fires of war get closer every night, or when there is a knock on the door in the middle of the night.

These things happen somewhere in the world every single day of the year, and the fortress port of Calais is a testament to the instinct to flee in search of safety.

Calais: The Final Frontier is broadcast on Saturday 31 January at 11:30 GMT on Our World on BBC World News and 21:30 GMT on the BBC News Channel.

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