A major US trade union on Thursday accused China of handing out hundreds of billions of dollars in illegal subsidies in a bid to dominate the green energy sector.
The United Steelworkers union petitioned the top US trade official to investigate practices it claims contravene World Trade Organization rules and cost US jobs.
"Right now, China is taking every possible step — many of them illegal under international trade laws — to ensure that it will control that sector," said union president Leo Gerard.
"America can't afford to cede more of its manufacturing base to China."
The union — one of the nation's largest — accused China of blocking access to materials used in green technologies, illegally linking subsidies to export sales, curbing imports and demanding foreign investors hand over technology secrets.
It also accused China of providing more than 216 billion dollars worth of subsidies to green technology makers "more than twice as much as the US spent in the sector and nearly half of the total 'green' stimulus spent worldwide."
The administration of President Barack Obama has 45 days to respond to the claims, which received immediate backing from some of his allies in Congress.
"This is a clear-cut violation, and we hope the administration will take up this complaint immediately. There is no question that China is ignoring trade rules so it can cheat its way to first place in the clean-energy manufacturing race," said New York Senator Charles Schumer, a Democrat.
"This is just the latest example of China's unfair trade practices, but it is one of the most damaging for US manufacturers. We will never meet our goal of increasing exports if we let China get away with this."