More than 136,000 people in the UK are believed to be trapped in modern slavery, according to recent figures.
Some campaigners say they're concerned that the pandemic may make the situation even worse, with millions more around the world left vulnerable to exploitation from traffickers.
In a letter to The Times newspaper, 17 church and charity leaders say they want to ensure that the Government's Nationality and Borders Bill doesn't create further vulnerability.
One of the signatories is Caroline Virgo from the Church of England's Clewer Initiative, which enables dioceses and wider Church networks to develop strategies to detect modern slavery in their communities and help provide victim support and care.
She tells Premier that modern slavery is hidden in plain sight:
"I think I can illustrate that by a story of something that happened to me about a week ago. I live in one of the largest cities in this country and we have a problem with forced begging. As I was walking to the local shopping mall, I noticed over the course of about half an hour, maybe ten people begging for money, always with a sign saying that they were hungry and that they were homeless.
"What was really interesting about these people is they had signs that looked all similar. They were always non-cardboard, or written in the same sort of pen, but crucially, they were saying that they were people that were homeless, but they had no belongings with them at all. They were just sitting there by themselves on the pavement. But if you have any familiarity with homelessness, you will know it's very unusual for people who are homeless to travel with nothing at all, they usually have a backpack or something like that with them. So, this will be an example of modern slavery hidden in plain sight.
"I spoke to the police about it yesterday at a service that we did at Bristol Cathedral - they admitted that there is a problem, which is affecting a lot of the southwest of England."
Caroline Virgo is urging the Government to listen to the voices of those who have experience of exploitation:
"I think that one of the things that a large number of charities feel is that the policies that governments have around this issue have become quite rigid. There seems to be very little space within them for actually listening to what survivors say or to people who will potentially be victims of modern slavery. So I think that we're faced with a system that very often seems cumbersome, that seems very unfair to the people who are trapped within it. Also for those of us working with the system, we find it hard to reconcile some of the difficulties with the Government's stated intention to do something about the problem."
Commenting on the Nationality and Borders Bill, Caroline Virgo said:
"I can't give an expert voice on that, but we've done consultations within our own department, within the Church of England and within the wider anti-slavery sector and I think there is a concern that it may at the best not improve the problem. Potentially it may make things more difficult. We are unfortunately developing a very difficult attitude towards people coming into this country that don't have the right legal papers and who knows how that will play out?
"Modern slavery is an organised crime, organised by very clever people who want to make as much money as possible. What I would like to see is that all of us, that's all the British public, and particularly the church community, take the time to understand what the issues of slavery are, what trafficking can look like, what the person who's being exploited within our society looks like, and I would like people to actually report these crimes to the police or to the modern slavery helpline. I would like people to think about who they're giving money to on the streets, which services they're providing for and really take the time to help themselves understand about this phenomenon that we have that is rife in this country."
Jane Yeomans is from the charity Transformation Cornwall which co-ordinates faith based social action. It has produced a toolkit of resources for helping communities combat modern slavery:
"Churches and faith groups are absolutely embedded in our communities working with services that are supporting the most vulnerable people. We're a great network to help get the word out and make sure we're not complacent in not seeing something. We've got to change the situation and it's time to step up to the mark. It's horrific what is happening and we need to spread the word that this is a massively growing crime and that we can do something about it."