The UK risks becoming a dumping ground for the products of forced labour from Xinjiang province in China if it rejects reforms proposed by members of the foreign affairs select committee with cross-party support, ministers have been warned. An amendment to the energy bill, due to be debated on Tuesday, would require solar energy companies to prove that their supply chains are free of slave labour. The Xinjiang region is the source of 35%-40% of the world’s solar-grade polysilicon, the key raw material in the solar photovoltaic supply chain. The amendment to the energy bill has been tabled by Alicia Kearns, the chair of the foreign affairs select committee, seven other members of her committee and a host of other senior backbenchers. It would require the Planning Inspectorate in England to ban any nationally significant infrastructure project over 50MW if it could not be proven beyond doubt that slave labour had not been involved. The new confrontation between parliament and the executive comes days after the foreign secretary, James Cleverly, returned from Beijing insisting that he had put human rights at the centre of the bilateral relationship. Kearns told the Guardian: “Cleverly talked the talk on the Uyghur genocide in Beijing. It’s time for the government to put its legislative might behind its strong rhetoric. By adopting this amendment to the energy bill, they can ensure that nationally significant infrastructure projects are far more transparent and become more free from forced labour. “Taking even this small stand against all forms of slave labour would help put an end to the UK becoming a dumping ground for slave labour-produced solar. Uyghur blood labour must not stain our countryside. “The fight against forced labour is a collective responsibility. Together, we must pave a path towards a clean energy transition, without becoming complicit in not just slavery, but genocide.” A letter signed by 15 human rights groups in the Coalition to End Forced Labour in the Uyghur Region says forced labour is rife in Xinjiang and sets a high bar, arguing: “Due to systemic use of forced labour in the region, there is no valid means for companies to verify that any workplace in the Uyghur region is free of forced labour or to prevent the use of forced labour in the region in line with human rights due diligence.” China and parts of the UK’s renewable industry will be furious if the UK backs legislation that its detractors say will lead to an effective ban on trade with the Uyghur region. Cleverly last week ventured on the first trip to China by a UK foreign secretary in five years in a bid to put relations with Beijing on a better business footing. Cleverly insisted that he had raised human rights in all his meetings with officials. But the cross-party determination by British MPs not to abandon the human rights agenda in China also creates a difficult backdrop for the subsequent visit by the investment minister, Lord Johnson, along with one of the largest British business delegations to a Chinese trade fair. The Modern Slavery Act requires UK companies to report on what they are doing to free their supply chains from slave labour, but places no duty on them to do anything other than report. The Coalition to End Forced Labour accepts that there has been some movement by solar companies to exit the Uyghur region in recent years, but says many firms are still operating there, especially with a view to supplying the UK market – where regulations are looser than in the US and EU. The amendment requires companies to submit a report to the Planning Inspectorate “to demonstrate clear and convincing evidence that the good, or the materials in the good, were not mined, produced or manufactured wholly or in part by forced labour”. Critics will argue that the amendment sets such a high bar in requiring the proof of no forced labour that it would in effect amount to a ban on British trade with Xinjiang province. They claim parallel legislation passed in the US has led to delays in the installation of solar equipment. The US Bureau of Labor estimates that “100,000 Uyghurs and other ethnic minority ex-detainees in China may be working in conditions of forced labour following detention in re-education camps. Many more rural poor workers also may experience coercion without detention.” In 2021 the US bureau added polysilicon to the list of items “produced by forced labour by Muslim minorities in China”. It argues that Uyghurs are now forced to work not just in Xinjiang but elsewhere in China. Both the Foreign Office and Labour frontbench have been asked to comment.