Britain vowed on Thursday to tackle modern slavery in government supply chains as it shared an action plan to encourage other countries to follow suit, acknowledging a tough road ahead.

The British government identified electronics, construction and service providers of cleaners and cooks as the riskiest sectors for slave labor, and said it had worked with about 400 of its suppliers to improve their anti-slavery measures...

Britain’s 2015 Modern Slavery Act requires companies whose turnover exceeds 36 million pounds ($43.6 million) to produce an annual statement detailing the actions they have taken to combat slavery in their operations, but does not include public bodies.

Public procurement is estimated to account for 15-20% of global gross domestic product, yet campaigners say efforts to combat supply chain slavery have been mostly led by big brands...

Labor rights groups welcomed the plan but urged the government to widen the scope of the Modern Slavery Act...

The law has faced widespread criticism in recent years and come under government review...

“The government must ... ensure that its suppliers hear the message loud and clear that exploiting ... workers to fulfil government contracts will not be tolerated,” said Phil Bloomer, head of the Business and Human Rights Resource Centre (BHRRC)...