The rugged beauty of southern Spain's coastline is well-known for attracting Europe's wealthy with time to play. It also receives attention from across the narrow stretch of water, on the African shores of Morocco. For many, the 10 miles or so of sea are the final barrier between them and the riches of Europe, exotic fantasies hinted at by the words, images and brand names which float across the strait on television airwaves.

It is not known how many attempt to make the crossing each year, stowed away in commercial ships or crowded onto pateras, rudimentary craft unsuited to the treacherous waters where the Mediterranean meets the Atlantic. Last year, 11,000 were caught in the attempt. Bodies wash up on Spanish beaches daily. One unofficial estimate talks about a thousand drowned each year. It is carnage.

Those who make it find themselves in a Europe without internal borders and an increasing need for hired labour. The EU estimates that in 2000 alone, half a million illegal immigrants crossed its borders; it also recognises that over the next 50 years, between 50m and 75m extra workers will be required to prevent a shortfall in productivity. With an extremely low birth-rate of around one child per woman, Spain is at the forefront of a possible labour crisis. Perhaps some 10m new workers will have to be found.

For Moroccans, 45% of whom earn less than $1.50 a day, the incentive to take up the slack in the European market is virtually irresistible, particularly for the 40% of the population under 16 years old. Few of them can expect to enter a trade. Many become homeless and drift towards the city ports in the north like Tangier and the Spanish enclave of Ceuta.

According to Mohammed Nahil, a sociologist specialising in street kids, the recent phenomenon of crossing the strait in the pateras began with the unknown hordes of homeless children. He says 80% are street kids, who, on arrival, let their friends know that they are safe and have found casual work. These friends will be the next to risk everything.

In fact, they have little to lose. Homeless children in Morocco receive little help from the state. There are one or two refuges, but they merely take the children in for a warm meal at night, leaving them to their own devices during the day. Their education comes from surviving, albeit by stealing and prostitution. The street kid simply seeks to prolong his life in any way he can.

"Officially," explains Mohammed, "he doesn't exist. He begins to get his values from the street. The 'value' of sex, his sex. The 'value' of stealing. There is no-one else. He has to be the father of himself."

Almost all street children are boys; girls go out independently into the street only when they are grown up. To break their parents' laws would see them labelled as prostitutes. Boys bear the brunt of this particular plight for several reasons: failure at school, divorce and re-marriage creates 'unwanted' children, and some are born outside a normal family environment and grow up as orphans.

According to Mohammed, Moroccan society hasn't arrived at a point where it can recognise that children are being born in the street. Religious conservatism has created a mental block. "If we say that there are children born outside marriage, it means there are mothers without husbands. And that cannot be."

There are no official statistics, only estimates which run into hundreds of thousands. Desperate poverty has created a tendency for the young to migrate from the countryside towards the coastal cities. Ceuta is a favoured destination as, once inside, they are on European soil and Spanish law means they cannot be forcibly repatriated. On average, 25 children are picked up by the police in Ceuta every day. They are taken to an official shelter from which they tend to escape again to lead lives of petty crime and solvent abuse on the streets.

Despite this terrible reality, "Ceuta is the first stage of a golden dream for these children. This dream is fed by the communications media in the form of Spanish football, TV and radio." This is the view of Ramona Tellechea, a Spanish national who works in Tangier with juvenile delinquents, most of whom are street kids, hustling their way towards a passage to Europe.

One of her charges is Ismael, a serious boy of 15, who says he doesn't know why "some foreigner" accused him of taking his wallet while "helping out" in Tangier's main port. He and his fellow detainees, many sporting replica Spanish football tops, are, perhaps, the lucky ones. At the centre run by a European charity they are taught basic skills, some IT and other vocational training like hairdressing in a mini-barber's shop. Some may find their way in life. Others will continue to dream of escape to the land beyond the Spanish shoreline visible over the walls of the institution.

The desire to emigrate is becoming a kind of incurable disease; an epidemic. Mohammed Nahil knew a boy who came from a prosperous background, but that wasn't enough for him to stay. His father wasn't willing to hand over responsibility for the family business to him. He left. "Crossing the strait is now all that children dream about," he says. "It is paradise."