Theresa May's decision to prioritise ending modern slavery and human trafficking will not have come as a surprise to Christian leaders in the UK.

For when she became prime minister last month, Cardinal Vincent Nichols specifically highlighted her work in the area and predicted that she would use her position in Number Ten to pursue it further.

Nichols, who attended a Vatican conference on human trafficking with May in 2014, wrote to her: "I thank you for the remarkable work you have accomplished for the victims of human trafficking, including your strong personal support for the establishment of the Santa Marta Group, demonstrated through your presence at its first meeting in Rome. This is a clear indication not only of your determination to use high political office for the protection of some of the world's most vulnerable people..."

Also in 2014, the Archbishop of Canterbury, Justin Welby joined Pope Francis in launching an ecumenical initiative to combat modern slavery and human trafficking. Archbishop Welby said: "We are struggling against evil in secret places and in deeply entrenched networks of malice and cruelty. No one of us is strong enough, but together we are ready for the challenge God is placing before us today, and we know that he will strengthen us so that all people may live in freedom and dignity."

Now, May has outlined her plan to end modern slavery in an article for the Sunday Telegraph which announced the introduction of a new Cabinet task-force and £33 million set aside from the aid budget to fund initiatives overseas.

The problem is international but also domestic. There are an estimated 45 million victims around the world. Albania, Nigeria, Vietnam, Romania and Poland are the most common countries of origin, but in 2013, 90 victims were found to be from the UK.

Cardinal Nichols' spokesman told Christian Today: "The Prime Minister's renewed commitment and her announcement of increased resources to fight modern slavery and human trafficking is welcome. Human trafficking is, as Pope Francis said, 'an open wound on the body of contemporary society' and Theresa May's resolve and commitment in this struggle demonstrates principled leadership."

May has form in seeking to tackle these dreadful crimes. Last year, as Home Secretary, she brought forward the Modern Slavery Act which introduced tough prison sentences for "slave masters", extended police powers and forced businesses into further transparency over whether such practices are taking place in the work-place.

In her article yesterday, she highlighted some of the crimes she is targeting: "From nail bars and car washes to sheds and run-down caravans, people are enduring experiences that are simply horrifying in their inhumanity. Vulnerable people who have travelled long distances, believing they were heading for legitimate jobs, are finding they have been duped, forced into hard labour, and then locked up and abused. Innocent individuals are being tricked into prostitution, often by people they thought they could trust. Children are being made to pick-pocket on the streets and steal from cash machines."

She concluded: "These crimes must be stopped and the victims of modern slavery must go free. This is the great human rights issue of our time, and as Prime Minister I am determined that we will make it a national and international mission to rid our world of this barbaric evil. Just as it was Britain that took an historic stand to ban slavery two centuries ago, so Britain will once again lead the way in defeating modern slavery and preserving the freedoms and values that have defined our country for generations."

May's Government certainly has much to do. Of the 10,000-13,000 modern slavery victims in the UK in 2014, only 2,340 were officially reported and recorded. Indeed, an independent review of the Act May introduced has found that between April 2015 and March 2016, six of the 43 territorial police forces did not record a single modern slavery crime. In response to this, May also announced that she is commissioning an HMIC Inspection "to make sure that all police forces treat this crime with the priority it deserves".

Some remain unconvinced. Sarah Champion, Labour's shadow minister for preventing abuse, said government cuts to police forces and local authorities had left a lack of resources. She cited figures showing that last year, 982 children were identified as victims of modern slavery and taken into local authority care, but within days, 60 percent of those had gone missing, presumed to be back with their traffickers. "We must be doing more to prevent this horrendous crime but, looking at her [May's] track record as Home Secretary, I'm not optimistic," Champion said.

But charities who work daily to tackle these crimes welcomed May's intervention. Neil Wain, the European programme director of Hope for Justice, told Christian Today: "We were delighted to hear the Prime Minister saying that her Government will prioritise the fight against modern day slavery. Hope for Justice have been working closely with a number of police forces around the country through training, building capacity and supporting operational efforts to tackle this crime. We welcome the comments she has made and we are looking forward to working more closely with our Government and police forces to eradicate this barbaric evil."