£1bn Pembroke Power Station faces EU permits probe
The European Commission has launched an investigation into the UK government's approval of the Pembroke gas power station.
It follows a complaint made by Friends of the Earth Cymru about the plant's impact on marine life.
It is argued European laws have been broken by allowing the power station to use water from the Cleddau estuary to cool its gas turbines.
BBC Wales environment correspondent Iolo ap Dafydd explained the background of the story to Oliver Hides.