Maria* was first brought to London in 2009. The 45-year-old, originally from the Philippines, began working with a wealthy Saudi family in 2013. She says she was promised the minimum wage and one day off each week. Instead, she worked up to 20 hours a day, seven days a week, without pay, and her employers held on to her passport “for safekeeping”. Passport or visa confiscation is a common kafala practice, designed to ensure cooperation, and is often accompanied by explicit or implied threats of deportation. “I didn’t know where I was,” says Maria. “I didn’t know my rights. I thought if I left, I would be arrested.”