The president of the European commission has refused to compromise on plans to cut greenhouse gas emissions and boost renewable energy sources and biofuels in the 27-nation bloc.
"Do not expect us to compromise on European interests," Jose Manuel Barroso told MEPs.
"Both our international credibility and credibility before European Union citizens depend on fulfilment of the targets."
Moving to a low carbon community would not be an easy task, he said, but one which necessitated a serious and clear commitment.
Several nations including France, Germany and Spain have complained about proposed targets - set to be unveiled next week - to cut CO2 emissions by 20 per cent by 2020, compared to 1990 levels.
Mr Barroso said the new policies would reflect the three central challenges of energy: competitiveness, sustainability and security of supply.
According to draft proposals seen by press agencies, the EU commission will vary contributions from each country based on gross domestic product per capita.
For regular email updates please submit your email address below.
Call 0800 512 012 for free, independent and local energy saving advice
Click here to request a call back from your local advice centre.
Latest News