The Salvation Army says it has seen nearly a fivefold rise in the number of slavery victims it has helped in England and Wales since 2012.
The charity says it supported 1,805 people from April 2015 to March 2016. By comparison, it had 378 referrals between July 2011 and June 2012 - its first year of operating the government contract to support victims.
One slavery victim said she came to England from south-east Asia to work as a servant in the home of a wealthy family. She says she was forced to work 14 hours a day for less than £100 a week, and that she even had to work on building sites. "I felt like a chained dog. It was like I was digging my own grave. Even though I'm out now, I still feel like I'm in chains. I still have nightmares that my boss is chasing me."
Anne Read, director of anti-trafficking and modern slavery at the Salvation Army, said that the minimum 45-day reflection and recovery period granted by the government for victims of human trafficking or slavery was insufficient. "If victims don't get the support that they need, then the potential is that they could, once again, be exploited and that's the worst thing that could happen as far as we're concerned. Forty-five days isn't long enough to support somebody - it gives them a chance to breathe, perhaps to recover their status quo, but it is only the very start of the process."
The Salvation Army said that:
44% of its referrals had been subjected to sexual exploitation
42% had been victims of labour exploitation - working within industries such as agriculture and construction
13% had been held in domestic servitude
Home Office figures estimate there are between 10,000 and 13,000 victims of modern slavery in the UK, with 45 million victims worldwide.