Renewable Transport Fuel Obligations (Amendment) Order 2009

I am extremely grateful for the contributions of my noble friend Lord Eccles and the noble Lord, Lord Palmer, who obviously know far more about the subject than I do. I have one question for the Minister arising from their contributions. Can he alter the RTFO to discriminate between UK biofuels, when he knows that they are not displacing other food crops or having undesirable effects, and those of overseas suppliers which are known to be producing the fuels unsustainably; or is he precluded from doing that by the free market rules?