Shackles which were used to tether slaves on display at the International Slavery Museum on February 9, 2012 in Liverpool.
Shackles which were used to tether slaves on display at the International Slavery Museum on February 9, 2012 in Liverpool, England. (Photo: Christopher Furlong/Getty Images)

Major retailer Marks & Spencer topped a list ranking Britain’s biggest businesses on their efforts to tackle modern slavery, yet labour experts urged the country’s top 100 companies to be more transparent and lead by example globally.

Supermarket Tesco and British American Tobacco ranked second and third on the first Global Governance FTSE 100 League Table, which judged firms based on their compliance with Britain’s landmark anti-slavery law, and overall human rights practices.

Under Britain’s 2015 Modern Slavery Act, companies with a turnover of more than £36 million must produce an annual statement outlining the actions they have taken to identify and stop forced labour in their supply chains.

Big brands in Britain and beyond are facing growing pressure from regulators and consumers alike to ensure that their global operations and products are not tainted by modern-day slavery.

“However unwittingly, through their global supply chains, businesses are complicit (in modern slavery and human rights abuses),” said Shamir Ghumra, a director at the Building Research Establishment (BRE), which backed the inaugural index.

The FTSE 100 companies have a combined market capitalisation of £1.9 trillion, own about 30,000 subsidiaries globally, and employ 6.8 million people, according to communications business Sustain Worldwide – which facilitated the ranking.

While most of the companies on index were found to be largely compliant with the requirements of the law, only one in four of the companies were fully in line, their research found.

The average combined score of the 100 companies – 47 percent – shows that they are generally failing to take meaningful anti-slavery action and spur better practices in the private sector, according to Caroline Robinson of Focus on Labour Exploitation.

“FTSE 100 businesses have the power to impact the operating practices of hundreds of thousands of companies around the world, due to their extensive supply chains,” Robinson said.

“It is time for government to enforce the (anti-slavery) legislation properly, introducing penalties for companies which fail to comply and mandating the actions businesses should take,” the charity’s head told the Thomson Reuters Foundation.

Home Office last week said it would write to the heads of all businesses covered by the law and that those who failed to take action could expect to face “tougher consequences”, such as being named and shamed publicly.

Just over half of the about 19,000 companies required to comply with the law have issued statements to date, according to Transparency in the Supply Chain (TISC) – a public database.

Hailed as a global leader in the anti-slavery drive, Britain said in July it would review its 2015 law amid criticism that it is not being used fully to jail traffickers, help victims, or drive companies to spot and stop forced labour.