Mr Cooper argues that inter-country variations in price and expenditure structure constitute an insurmountable obstacle to meaningful measurement of differences in the purchasing power of currencies.
But the US appears to be growing as an obstacle, with campaigners acknowledging privately that the balance of power in Congress is likely to become even less favourable to carbon-cutting legislation after the next round of elections in 2012.
The regulator will also possess the power to set maximum prices for interconnections, currently seen as being a severe obstacle to the emergence of rival firms in the fixed-line and wireless market.