Governments are failing to properly tackle the scourge of slavery and human trafficking even as it increases, the former UK prime minister Theresa May has said. Modern slavery is “slipping down the agenda” among world leaders, she told an audience at the World Economic Forum in Davos. “We’ve seen in recent years the number of people in slavery increasing around the world,” she said. “Conflict, the pandemic, the impact of climate change increase vulnerability to it. At the same time governments are taking their attention off it.” May, who heads the Global Commission on Modern Slavery and Human Trafficking, was speaking at an event on modern slavery at the Swiss ski resort alongside Princess Eugenie, who co-founded the Anti-Slavery Collective in 2017. “Guns and drugs can be only trafficked once but human beings are trafficked again and again and again,” Eugenie said. “For them it happens every day and minute.” May said companies “need to really pay attention to supply chains” and governments should set tighter laws. Intergovernmental organisations such as the G7 and G20 also need to take the problem seriously and have it on their agendas, she said. May, who was home secretary between 2010 and 2016 and prime minister between 2016 and 2019, said modern slavery is hard to spot. “Go out on to the streets [and] most people tell you it was eradicated 100 years ago. Sadly it is not. There are people probably not that far from where we are today who are in slavery,” she added. José Manuel Barroso, a former European Commission president who heads the board of Gavi, the global vaccine alliance, said increasing migration will move modern slavery higher up the agenda. “This is something that is real and it deserves more attention,” he said. John Schultz, the chief operating officer at Hewlett-Packard Enterprise, said the biggest problem is that modern slavery is an “out of sight, out of mind” issue. “We have to get this issue back up to the boards of directors and CEOs where they view it as a top priority,” he added. Eugenie founded the Anti-Slavery Collective with her friend Julia de Boinville to raise awareness of the estimated 50 million people in modern slavery around the world.