Australian faith leaders, including prominent Christian leaders, have joined in calling on the Australian Government to take the first steps to a Modern Slavery Act aimed at discouraging slave-like conditions in Australia and overseas.

The call is contained in an open letter to the Prime Minister Malcolm Turnbull released late last week to mark a year since the launch of the Australian Freedom Network and the annual International Day for the Abolition of Slavery.

Signatories to the letter include James Condon, former Salvation Army commissioner and chair of the Australian Freedom Network, Archbishop Philip Freier, the Anglican primate of Australia, Archbishop Denis Hart, president of the Australian Catholic Bishops Conference, Brian Houston, global senior pastor and founder of Hillsong Church, and, Bishop Daniel, of the Coptic Orthodox Church of Australia, Sydney and Affliated Regions as well as leaders from the Muslim, Buddhist, Hindu and Jewish communities.

In the letter, the religious leaders say that while Australia has "robust" legislation criminalising the spectrum of slavery and slavery-like practices, "we believe a Modern Slavery Act would be a vital next step".

"Australia has an opportunity to lead and an opportunity to learn from what has worked and not worked in other countries to identify, mitigate and eradicate modern slavery."

The letter says that while the leaders have welcomed commitments to curb exploitation in some industries, they "express our concerns about the welfare and human rights of thousands of migrant workers who are either at risk of or are experiencing forced labour in Australia".

"We believe it is vital that Australian governments and businesses take all reasonable steps to ensure their procurement activities ensure the people producing the goods or services have decent jobs and are free from forced labour or human trafficking."

In a statement released with the letter, Mr Condon said while Australia has a solid judicial framework to criminalise human trafficking and forced labour, "it is clear we can and need to do more". 

"Last year the UK Government showed great global leadership by introducing a Modern Slavery Act that significantly raised community awareness, increased identification, reporting and care for victims. The Australian community and business need to begin the discussion about taking this path.”

Under the UK Act, large businesses are obliged to report on steps they have taken to ensure that slavery and human trafficking are not taking place in their business or in their supply chains. The Act also established the independent position of Anti-Slavery Commissioner.

According to the Global Slavery Index, it is estimated that more than 45.8 million people in 167 countries live in some form of modern slavery, including an estimated 4,300 people in Australia.