"I'm really excited about the principle of GB Energy," she told BBC News. "But it's taxpayers' money and we should not be supporting slave labour with that money. And wherever possible, we should be supporting good working practices and buy British if we can." She added: "That means that yes, unfortunately, in the short term, solar panels are probably going to be slightly more expensive. "There are solar panels made around the world in Taiwan, Canada, even in the UK." Longi and Aiko both told the BBC they forbid forced labour in their production and supply chains. China is the world's leading producer of solar panels and the suppliers in the Xinjiang region have been linked to the alleged exploitation of Uyghur Muslims. Earlier this year, the law was changed to ban GB Energy from investing in renewables if there is evidence of modern slavery in their production. China has dominated the market and, according to the International Energy Agency, the country's global share in all the manufacturing stages of solar panels exceeds 80%. Champion, who is chair of the International Development Select Committee, said "abuse in renewable supply chains is insidious and hard to root out". But she urged ministers to exclude known human-rights offenders from winning public contracts. A GB Energy spokesperson said all of the solar contracts issued under the schools initiative complied with the UK's modern slavery rules.