Senate lawmakers and the Obama administration on Wednesday stiffened their opposition to a European law that targets emissions from commercial jetliners and applied new pressure on Brussels and the United Nations to resolve global concerns.

In a rare display of election-year bipartisanship, Democratic and Republican members of the Commerce Committee and the administration's top transportation official called the EU standard that puts a price on pollution unworkable.

"The European Union acted because it believes it needed to make a bold effort to reduce greenhouse gas emissions and I understand why they did so. But, I believe that their unilateral action is likely not sustainable by international law," the panel's chairman, Jay Rockefeller, said at a hearing. "I support the goals, but I have to oppose the action."

Kay Bailey Hutchison, the committee's top Republican, said that she and Rockefeller "are in agreement" on the primary point.

"The European Union, with this emissions trading scheme, is acting outside of their prerogative and most certainly will have a negative effect on our aviation community," she said. "The EU needs to step back."