By Emma-Jane Kirby
BBC Paris Correspondent
Some migrants pay smugglers to help them enter the UK
On a slip road close to the port of Calais in northern France, a group of dusty Afghan men are huddled around a single tap, filling water bottles and washing their feet.
They have only recently got this facility - until some weeks ago, most of the migrants washed in the sea or in waste water next to a chemical plant.
Hamkar, a 17-year-old from Helmand Province, looks weary and hot but he says he is happy to have the tap because at least now he can try to wash once a week.
The only problem is finding a moment of privacy because this one tap is shared with around 800 other members of "the jungle".
"The jungle" is the main illegal makeshift camp that sprang up in the woods around the Calais port shortly after the closure of the Red Cross Reception Centre at Sangatte in November 2002.
It was hoped that shutting down Sangatte, which was a magnet for migrants trying to cross the Channel to Britain, would stem the flow of refugees and asylum seekers, but instead numbers have swelled.
The increase has prompted the UN Refugee Agency to set up a permanent office in the northern port to offer asylum advice and to help migrants make informed decisions.
"Every day the people are increasing here," said Mussa, a shy young Afghan in his early twenties.
"They're trying to go to England but they don't know about the conditions of this jungle. If they knew about the conditions of this jungle, they would not come."
He invited me to take a look for myself and I followed him through the sands into the trees.
One hundred metres into the woods and I am in the heart of the makeshift, insanitary campsite.
It is a sort of shanty town and there is so much rubbish and litter lying about, it looks as if it has been built in the middle of a huge landfill site.
Tents have been made out of metal grilles and chicken wire which have been covered by plastic sheeting and bin liners - in Mussa's tent, which is about 10ft square, the roof has been patched over with a sheet of birthday paper.
Mussa told me that eight people sleep here regularly but sometimes they have to make room for 10.
Inside the tent, it is stiflingly hot and the bits of old carpet and car floor mats that line the floor are giving off a smell like old meat.
The French are under pressure to prevent migrants entering the UK
There are no beds or mattresses. One of Mussa's friends said they often had skin problems and strange itches.
Twenty-year-old Nassid from Helmand Province has been in the jungle for six months and is determined to make it to Britain.
He tries twice a day to climb aboard lorries and trucks to cross the Channel undetected but each time he has been discovered.
He knows the routine perfectly now - a quick trip to the police station, a written warning, sometimes a court appearance, but then he is just set free to return to the jungle and to make a new attempt.
Ten of his friends he claims have already succeeded in getting to the UK.
"Britain has a good government" he said, "Britain will help me to get a better life."
I asked him if he has paid people traffickers to help him get to Britain but he shook his head and said he had no money. He had to try alone, he explained, which made things very difficult so he had to try twice a day.
Most of the migrants do pay smugglers to help them get across. Last April the Calais police launched a major raid to try to break up the trafficking rings, arresting more than 190 migrants and bulldozing tents.
But the migrants just came back. In dealing with the problem, the French authorities have a difficult balancing act - they cannot leave the migrants to starve but equally, they cannot offer too much humanitarian aid in case it encourages even more to come here.
But Vincent from the charity group Salaam, which provides a soup kitchen and clothes for the jungle's inhabitants, believes the government has to do much more to help.
He said: "Currently it's only volunteers with the immigrants. And if tomorrow we decided to stop, what would happen?"
"If they needed to eat, what would they do? They would maybe go to the shop and steal what they need to survive. "
Vincent pointed to a dirty cotton sheet in Mussa's tent and asked how he was supposed to keep warm with just that.
He said they used to have more, but the riot police raided the tent and sprayed tear gas all over their clothes and blankets.
He added: "They were forced to throw them out because they couldn't use them again.
"But what do the police think - that with no blankets the people here will be forced to go home and the problem will just go away?"
In fact, Vincent and his organisation have to be very careful with the type of aid they give.
In France, housing and transporting undocumented migrants is a crime which can result in hefty fines or even prison sentences.
A recent hit film here, called Welcome, showed a Calais-based swimming coach helping a Kurdish teenager to train to swim the Channel to Britain - when he invited the desperate young boy home, his neighbours informed the police.
The film, with its resonances of World War II deportations, caused a political storm.
It managed to portray the huge dilemma of this seaside town. With 14% unemployment, many residents loathe the presence of the refugees while others loathe the fact that in civilised France, men are forced to bathe in waste water from a chemical plant.
The French authorities are under growing pressure from Britain to stem the tide of migrants trying to cross the Channel.
But the French government has also called upon Britain to tighten its controls, warning that migrants still see the British illegal job market as the promised land.
Many of the migrants in the jungle say that with no identity card system, Britain is a much easier place for an illegal immigrant to find work.
The French and British governments are currently discussing the creation of a new immigrant holding centre within the British side of the Calais docks which would allow London and Paris to break through the quagmire of asylum law to send illegal immigrants home more easily.
In Mussa's tent Khab, who has run away from family feuds in his native Kabul, asked why Britain cannot just end the misery and let in the 800 men in the jungle.
He said: "We have come here because we had problems in Afghanistan - we are not here for enjoyment.
"We have problems with water, we have problems with doctors, we have problems with sleep. I just want to say help. Please help."