The Commission opened the debate on a future common European Energy Policy with the publication of a 'Green Paper' in March 2006. Suggestions include completing the opening of European gas and electricity markets and stepping up relations with major suppliers such as Russia and OPEC. Other key suggestions include boosting renewable energies, energy efficiency, and research on low-carbon technologies. However, EU member states have already made clear that they would not tolerate interference with national sovereignty, especially when it comes to taking sensitive political decisions such as opting for nuclear power.