WASHINGTON (CNN) – House Democratic leaders are furiously lobbying their members and moderate Republicans to support a landmark energy bill in the face of resistance from some conservative members of their own party, and staunch opposition from the GOP — roadblocks that are making it difficult to find the 218 votes necessary to pass the measure, according to Democratic leadership aides.

A vote on the Clean Energy and Security Act, which would restrict emissions of green house gases and require use of alternative energy in an effort to slow the effects of global warming, is scheduled for Friday.

"There is no question that the cap and trade bill will cost millions of jobs and it is pretty evident, I think now, given the word that we are hearing that the other side has 190 votes at this point, far short of that which are needed to pass this bill," said House Minority Whip Eric Cantor, R-Virginia.