They would also have to comply with new employment laws, such as the working time directive which guarantees employees four weeks' paid holiday a year.
One of the organisation's key concerns is that the government is not providing enough money to fully fund the 15 hours per week free nursery education that it guarantees all three- and four-year-olds in England.
The project, a joint venture between NRG and CPS, the San Antonio municipal utility, was one of four finalists for Department of Energy loan guarantees and at one point was thought to be a front-runner for the money.