Democrats in the U.S. Senate aim to debate in late July a bill clamping down on offshore oil drilling practices and fostering more alternative energy use, but no decision has been made on whether to include controversial climate change provisions, aides said on Friday.

Two Senate committees have cleared bills crafted to address aspects of the Gulf oil spill. But whether those measures will become vehicles for wider-ranging energy policy, or climate-change provisions, remains an open question.

Senate Democrats Thursday seized on the environmental disaster in the Gulf of Mexico as a reason to pass climate-change and energy legislation, but internal policy differences will not be easy to overcome and may also leave many disheartened.

WASHINGTON The Senate Thursday defeated 53-47 an effort to limit the Environmental Protection Agency's authority to regulate greenhouse gas emissions, and President Barack Obama said the vote was a reminder of the need to pass more comprehensive climate change legislation.

In the absence of congressional action on climate change, the Senate is heading toward a much-watched vote on whether the Obama administration should be allowed to go ahead with regulations curtailing greenhouse gas emissions from power plants and other major polluters.