Pembroke power station may breach eco law
10 December 2012 Last updated at 19:45 GMT
The new £1bn Pembroke power station may be forced to change its cooling system because of fears its technology may breach conservation laws.
A leaked document seen by BBC Wales says the European Commission is so concerned it has sent a formal notice of infringement to the UK government.
It lists 18 violations of four separate environment laws.
But RWE npower, which built the power station, said the plant's development had been thoroughly scrutinised.
BBC Wales environment correspondent Iolo ap Dafydd reports.