Human trafficking is a "huge and daunting challenge" but the churches must face up to it and help tackle the problem, according to the Archbishop of Canterbury, Justin Welby.

Archbishop Welby, who discussed the issue with Pope Francis earlier this year, said: "Evil will thrive if humanity stands by and does nothing while the most vulnerable suffer at the hands of traffickers and slavers."

He was speaking in a message of support to Anglicans meeting in Rome to discuss how churches can help end human trafficking and modern slavery.

The Archbishop and the Pope have made a joint commitment to fight on both fronts. With their blessing the Global Freedom Network, an ecumenical and inter-faith initiative, was launched in Rome in March 2014.

This week's consultation is being convened by the Anglican Alliance and hosted by the Archbishop of Canterbury's representative to the Holy See, Archbishop Sir David Moxon.

Archbishop Welby said: "This week you have gathered to consider how our Anglican Communion can be more effective in working together and collaborating with other faith communities and secular partners to end modern slavery."

A list of recommendations will be drawn up at the meeting to focus on prevention, as well as protection and support for survivors, prosecution of perpetrators and policy and advocacy work with governments and the private sector.

The delegates will also spend a day in prayer and reflection in the ancient town of Assisi, considering the ministry of St Francis with the most vulnerable and oppressed of his time.

According to recent estimates, nearly 30 million people are caught up in some form of slavery in almost every part of the world. The Anglican Alliance regards the issue as a global priority. Other organisations working to end the problems include the Global Freedom Network, Caritas Internationalis, the Salvation Army, and the Walk Free Foundation.

Rev Rachel Carnegie, co-executive director of the Anglican Alliance, said: "It is truly shocking and heartbreaking to hear the accounts of men, women and children who have been trafficked and enslaved. There are many important initiatives in different parts of the Anglican Communion. This consultation will enable us to learn together from our experiences and to shape a stronger collective response to end this crime against humanity."

Churches, individuals and communities worldwide are invited to join a one-hour global webinar on Thursday 6 November 2014 at 1pm GMT, which will share outcomes from the consultation and discuss the way forward for shared learning and collaboration across the Anglican Communion. Follow this link to register.