May in plea over 'evil' slavery
Business leaders have been urged by the Home Secretary to take immediate action to tackle the "evil" of modern-day slavery.
Addressing the Trust Women conference in London, Theresa May said companies must be confident they are not dealing with slave drivers.
She also said flight attendants should be given more power to report unusual behaviour in order to clamp down on human trafficking.
Mrs May's speech comes after a married couple were arrested on suspicion of being involved in forced labour and slavery after police rescued three women from a house in Brixton, south London.
Speaking in front of women's rights campaigners and representatives from law, finance, business, technology and Government sectors, the Home Secretary said: " We will all have read, and been appalled by, the news recently that three women had been kept imprisoned for 30 years in horrific conditions. That was in London in the 21st century."
Mrs May said she wanted the "private sector to play its part" in tackling the issue.
She went on: " Companies must be confident that they do not conduct business with suppliers involved in trafficking.
"But I would also like companies to take the initiative themselves," she said. "I do not think any of us want to rely on legislation. We would all like to see immediate action. We would like a commitment from each and every business in this room to look into their supply chain and make sure that there are no instances of labour exploitation."
The Home Secretary said the travel industry also had a role to play and praised airline Virgin Atlantic and holiday firm Thomas Cook, who have developed a human trafficking training package for flight attendants so they have more power to report unusual behaviour.
"I would strongly encourage others in the travel industry to follow," she added.
Ms May said that last year, nearly 1,200 potential victims of human trafficking were referred to the UK's central body for the collection of this information, known as the National Referral Mechanism (NRM) - a 25% rise on the previous year.
The Home Secretary said the operation of the NRM is to be reviewed to ensure it is working as effectively and as supportively as possible.
The Home Secretary outlined other measures taken by the Government to deal with the growing problem, including a Modern Slavery Bill, which will see increased sentences for slave drivers and enable the courts to restrict activity that puts others at risk.
As well as launching the National Crime Agency, which deals with human trafficking, a Modern Slavery Unit has been set up within the Home Office.
Mrs May said the unit will lead to "more arrests, more prosecutions, but most importantly, more people released from slavery".
The Home Secretary also pledged to clamp down on human trade in "source countries" to alert potential victims and to "disrupt the monsters who exploit them".
She added: "We will work with foreign governments to strengthen their knowledge and understanding of modern slavery and empower them to stop it."
Closing the speech, Mrs May said: "I am in this for the long term. Each step that we take contributes to the eventual eradication of slavery from our country.
"Together, we're going to shine a light on slavery and its evil. And the world is going to be a better place for it."
Aravindan Balakrishnan, 73, and wife Chanda, 67, were arrested by police amid allegations that they held three women for more than 30 years.
The alleged victims are a 30-year-old Briton, a 57-year-old Irish woman and a 69-year-old Malaysian, who are all now being cared for.
The couple are believed to have been well-known to the police in the 1970s after setting up a communist squat, the Mao Zedong Memorial Centre, in Acre Lane, Brixton in 1976.