The UK has backtracked on its pledge to ban slave labour from its renewable supply chain to meet Ed Miliband's Net Zero goals.
Labour enshrined in law a promise that its state-run company GB Energy (GBE) would not fund firms using forced labour, such as the China ones that dominate the market.
But a probe revealed that solar panels destined for schools came with no such guarantee that they were ethically manufactured.
And on Monday night, Mr Miliband's energy department rowed back, introducing a new caveat to say that it would only ensure panels were free from forced labour 'as far as possible'.
It came as the Government announced that it would push to rid the energy system of fossil fuels and focus on renewables instead.
The rush towards Net Zero leaves the UK reliant on solar panels from China. Many of the materials come from Xinjiang province, home to the Muslim Uyghur population who China has been accused of using as slave labour.
GBE has funded solar panels for schools and hospitals to provide renewable energy.
On Monday furious campaigners demanded that a previous commitment to 'measures for ensuring that slavery and human trafficking is not taking place in its business or supply chains' be upheld.
Ed Miliband's department has placed a caveat on its slave labour rules, saying now that solar panels destined for schools will only be free from the scourge 'as far as possible'
Sir Iain Duncan Smith, an arch China-sceptic, pointed to the legislation which he said had 'no caveat'.
But on Monday, a Government spokesman said: 'We have strict procurement controls to ensure that any solar panels are free from forced labour, as far as possible. All contracts issued under the schools and hospitals solar initiative complied with UK procurement rules, including extensive requirements under the Modern Slavery Act.'
Eleanor Lyons, the independent anti-slavery commissioner, said: 'The race to Net Zero should never come at the expense of people forced to produce goods in horrendous conditions, working endless hours and under constant surveillance.
'The Government promised taxpayers their money would not fund products linked to forced labour.'
Labour's admission came after Politico exposed that GB Energy had funded firms that cannot guarantee their supply chains are free from this risk.
It reported that the company had even awarded contracts to firms that human rights experts have identified as having a high risk of exposure to forced labour.