"It will be an opportunity for everybody to go on record, so folks at home will know how senators feel about this massive overregulation, which is going to have an extraordinarily adverse impact on our economy," Senate Minority Leader Mitch McConnell, R-Ky., told reporters Tuesday.
McConnell introduced an amendment to a small-business bill that would permanently block the Environmental Protection Agency from regulating greenhouse-gas emissions -- regulations that took effect in January.
He said on the Senate floor the EPA's plans to regulate carbon-dioxide emissions would further increase energy costs and eliminate thousands of jobs.
Two other amendments that would limit the EPA's climate authority include a measure from Sen. Jay Rockefeller, D-W.Va., to delay the rules for two years and a bill from Sen. Max Baucus, D-Mont., to exempt small polluters and the agriculture sector from climate rules.
"I think we're at a point where in the morning we can vote on the McConnell amendment dealing with the EPA and a couple of other amendments relating to EPA to get rid of that issue one way or the other," Senate Majority Leader Harry Reid, D-Nev., said on the Senate floor Tuesday.
He told reporters later he was not sure which way the votes would go. The bills need at least 60 votes to pass the 100-member Senate.
Companion legislation introduced in the House passed a key committee this month and was expected to be voted on by May.
The U.S. Supreme Court ruled April 2, 2007, the EPA had the authority to regulate the emission of greenhouse gases in automobile emissions. The court said the agency could not sidestep its authority to regulate those gases unless it could provide a scientific basis for its refusal.
That ruling overturned a Bush administration argument that the EPA did not have a right to regulate carbon dioxide and other heat-trapping gases under the U.S. Clean Air Act.
Regulating greenhouse-gas emissions is a key Obama administration energy initiative, and Wednesday's expected vote comes as President Barack Obama outlines a national energy policy "for America's energy security."
Obama pledged as a candidate to fight climate change and pushed for EPA greenhouse-gas regulation last year after Congress failed to pass legislation addressing the issue.
The United States fell to No. 3 in clean-energy investment, after China and Germany, a study by the independent, non-profit Pew Charitable Trusts' Pew Environment Group said Tuesday.
China drew 22 percent, or $54.4 billion, of 2010's total $243 billion in clean-energy investments, up from 2009's $39.1 billion, the Pew study said. Germany was second at $41.2 billion, up from $20.6 billion in 2009.
The United States drew $34 billion, up from $22.5 billion.
But the United States was No. 1 in clean-energy venture capital and private-equity financing, Pew said.
While these sorts of investments accounted for only $8.1 billion, or slightly more than 3 percent, of the $243 billion in clean-energy investments, the United States attracted $6 billion, or three-quarters of the total, Pew said.