The failure of the US Senate to enact comprehensive energy and climate legislation prior to the August recess likely dooms its prospects for 2010, despite vows by its most ardent supporters to press forward.

Instead of a sweeping bill, Senate Majority Leader Harry Reid (D-Nevada) is bringing narrow legislation to the Senate floor that will focus on the Gulf of Mexico oil spill, promotion of natural gas vehicles, home energy renovations and financing for the Land and Water Conservation Fund.

But it is unclear whether Reid has the votes to even get that through.

Efforts to include a carbon trading system and other elements of energy proposals when it became clear that supporters could not round up the 60 senators needed to overcome procedural attempts to block a vote before Congress leaves for the summer recess on 6 August.

John Kerry, co-author of the proposed Senate bill, vowed to keep working to find the 60 votes. He has insisted that legislation featuring carbon trading could still make it, either in the September session before legislators leave for their campaigns or in a lame-duck session after the mid-term elections.