CALAIS, France >> The migrants from Afghanistan, Sudan, Eritrea and elsewhere keep coming. Almost 100 a day arrive at this dusty, ramshackle camp perched at the edge of the English Channel, just 31 miles from Britain, their ultimate goal.

The French authorities have tried for 18 months to dismantle the vast camp, known as the Jungle. In their last attempt, in March, when about 4,000 people lived here, they leveled almost half of it. But since then, the camp has almost doubled in size. It is larger than ever, and it remains one of the most visible symbols of Europe’s inability to cope with the influx of so many desperate people.

Dazed and ragged, new migrants stumble up the industrial road from nearby Calais every day, past the graphite electrode factory and underneath the well-guarded highway overpass that serves as the entrance to the camp.

Space has grown so tight that the fresh arrivals, overwhelmingly young men, spend hours looking for a free spot to pitch their tents.

“The situation is like Africa in this Jungle,” said Mohammed Zakaria, a 25-year-old Sudanese man who shares a 12-by-7-foot tent with nine others. As bad as conditions are in Calais, he does not want to go back to Sudan.

But there is little chance for him or the others to press ahead. On Monday, President Francois Hollande of France reiterated his pledge to dismantle the camp. The French authorities have vowed to raze it by the end of the year, saying new demolitions will begin in October. Last week, amid clashes with the police, construction began on a high wall to keep migrants from trying to sneak aboard trucks bound for Britain.

Already, 12-foot-high fences topped with barbed wire stretch more than a mile along the highway to the port of Calais to prevent migrants from storming the cargo trucks entering the tunnel under the channel on their way to Britain. There are regular police sweeps with tear gas to keep migrants away.

Migrants and their smugglers deliberately induce accidents to stop traffic so they can board trucks. This month, fed-up truckers blocked traffic bound for Calais on the English side of the tunnel in protest.

With no income and no means to make money, the migrants have little to do with their time but to wait for any opportunity to cross into Britain.

One group supplies some migrants with SIM cards so they can phone their home countries, and men perch atop a hill to gain better reception.

In the meantime, the camp has taken on an air of increasing permanence, to the frustration of local people.

“For six months they’ve allowed construction to take place, they’ve allowed migrants to arrive,” said the mayor of Calais, Natacha Bouchart, who says the port is losing money and who has led protests against the camp. “There’s been a very sharp worsening of the situation.”

Humanitarian groups do much that the French authorities will not, including providing food and basic necessities. But shelters remain flimsy and hard to come by, leaving many migrants wet and cold.

Migrants are free to roam outside the camp, but they cannot go far without money and proper documentation.

Local officials and aid workers agree that the state’s attempt to clear the camp in March “was a failure,” as Yannick Le Bihan, director of Médecins du Monde, put it. “The authorities are always one step behind the situation on the ground.”

For most of the camp’s residents the goal is still to get to Britain, and the country’s vote in June to leave the European Union has not deterred the flow. “I don’t want to go to school,” said Zakaria, the Sudanese man. “I want to go to England.”