Like many migrants drawn to the French port of Calais, Ali, a 22-year-old Iraqi, is convinced his life will be better if he can make it across the 32-kilometer stretch of sea separating him from Britain.

"I know people in London. They can help me and it will be a new life," Ali said, speaking on the outskirts of a migrant slum in Calais. "It cannot be worse than in France."

Dislocated by war, political turmoil and poverty, 3,000 migrants are living in makeshift camps in and around Calais, hoping to find a way to the other side. If they make it, they expect to find employment, illicitly, in Britain's booming shadow economy, or claim asylum in a system often seen as more generous than France's.