"YOU may choose to look the other way, but you can never say again that you did not know." In this warning in 1791, William Wilberforce brought home to Parliament the reality of the Atlantic slave trade. Wilberforce, with a group known as the Clapham Sect, set out to raise public consciousness of the evil of the slave trade, and to seek its abolition.

Today, it is estimated that between 12 and 27 million people worldwide are enslaved into forced labour and sexual exploitation. However we do the sums, it means that there are more people enslaved today than at any other time in human history.

The Global Slavery Index 2013 identifies slavery in Britain: "Primarily originating from Africa, Asia, and Eastern Europe, victims of modern slavery are forced into sex work, domestic servitude, agriculture, construction, food processing, benefit fraud, door to door leaflet delivery, and also in tarmacking and block paving industries."

Wherever people live in the UK, it is possible that someone near by is a victim of trafficking. We are looking at a globalised industry, which makes huge profits for those who lure the vulnerable, and exploit the weak and desperate. Businesses need to check their supply chains: the everyday items we buy may well involve the forced labour of people somewhere in the world.

However it is defined, what trafficking comes down to is simple: it is about moving someone into - or keeping them in - a situation of exploitation from which he or she cannot escape. The recent freeing of three women who are believed to have been enslaved for many years in London has brought this into focus. Sometimes, as the police are saying about this case, the chains are invisible. Victims are abused, isolated, terrified, and often confused.
 

THIS is a situation that demands concerted action from the Church, as well as from the rest of society. Human Rights Day, 2 December, is focusing this year on trafficking. Attempts are being made in Parliament to bring in a new anti-slavery Bill. How successful this will be is determined by many things, including Parliamentary timetables. Whether or not such a Bill is passed, this in itself will not bring the outrage of modern slavery to an end.

"Open your mouth, judge righteously, defend the rights of the poor and the needy," the author of Proverbs wrote. The issue of trafficking requires similar voices and action. What is needed is a new global ethic on slavery and trafficking, one in which priority is given to prevention, to prosecuting the perpetrators, and to protecting the victims and supporting them to regain their lives.

We need to learn a new set of three Rs - rescue, rehabilitation, and re-integration. Prevention and response hold the key to a new international convention on abolishing slavery.

Christian people have a responsibility to practise solidarity with all those, regardless of status, who are dehumanised by forced labour or trafficking. Jesus's identification with us as human beings, made in God's image, is vital to understanding how we are to act.

Trafficked people have rights - not because of their citizenship, but because of their human nature. As human beings, they deserve the right to grow into the full stature of their humanity. We have an example of this in the Bible story of Joseph, who was sold into slavery by his brothers, trafficked into Egypt, and ultimately rose to save a nation.
 

THERE are things that we can do to fight this injustice. We can pray and take action. Everything that Christians do begins with prayer, because that is how God moves our hearts to his saving justice.

We can support those who are seeking to legislate for an anti-slavery Bill in letters, phone calls, and emails to MPs. We can raise funds for organisations that combat modern-day slavery.

We can learn more about it, and raise awareness with others. We might take a fresh look at our neighbourhood, at those engaged in industries such as agriculture, food-processing, domestic work, and so on. We could search for signs, particularly among women and girls - for people who display signs of fear, vulnerability, or hiddenness.

As a Church, we are planning to focus on modern slavery, developing study materials and training programmes, and collaborating with other Churches and organisations that are already working with great commitment in this field.

We want to raise consciousness of this 21st-century crime, so that we can say, with Wilberforce: "You may choose to look the other way, but you can never say again that you did not know."
 

The Most Revd Justin Welby is the Archbishop of Canterbury. The Rt Revd Peter Price is a former Bishop of Bath & Wells.