* Republican Senator Graham's support elusive
* Changes to oil drilling provisions in the works
* Waning support may stall bill this year, says lobbyist (Adds comments from White House, paragraphs 8-10)
By Richard Cowan
WASHINGTON, May 6 (Reuters) - A long-awaited bill to reduce pollution that contributes to global warming could be unveiled in the U.S. Senate next week, but likely without the public backing of an influential Republican lawmaker, Senator Joseph Lieberman said on Thursday.
"I hope so," Lieberman told reporters when asked whether next week would bring the public roll-out of the legislation being driven by Democratic Senator John Kerry.
Lieberman, an independent, has worked closely with Kerry and Republican Senator Lindsey Graham on the bill to achieve a 17 percent cut in U.S. emissions of carbon dioxide and other greenhouse gases by 2020, from 2005 levels.
Nearly two weeks ago, Graham said he would drop out of the effort if Democrats insisted on moving forward with unrelated immigration reform legislation this year.
"He'll be there in spirit and substance but probably not with us" on the podium at the anticipated event, Lieberman said of Graham.
Kerry said that Graham "stands by" the bill the three senators have crafted, but noted that immigration reform is also still on the Senate's radar screen.
Without Graham, it is unclear whether Kerry and Lieberman would be able to lure enough other Republicans to vote for the controversial climate bill that aims to reduce the use of high-polluting coal and oil as energy sources in favor of cleaner alternative fuels.
It is also unclear whether President Barack Obama is willing to make a big high-profile push to promote the bill, which some environmentalists think is necessary for any hope of passage.
When asked whether climate legislation stood in the long legislative queue, White House spokesman Robert Gibbs said it was clear the climate bill was further along than immigration.
"I think there's a lot of progress that has been made on energy legislation and I don't think anybody -- Democrat, Republican, or independent, in Joe Lieberman's case -- wants to see that work and that commitment walked away from," Gibbs told reporters.
COMPLICATIONS FROM GULF OIL SPILL
Lieberman also said that offshore oil drilling provisions of the climate bill were being ironed out in the aftermath of a major Gulf of Mexico oil spill. [ID:nN05211341]
"We're still talking about that," Lieberman told reporters. The bill had aimed to help expand drilling off the coasts of mid-Atlantic states, but new safety questions have arisen.
With thousands of barrels of oil threatening to spoil the shores of Louisiana, Mississippi, Alabama, Florida and possibly even states on the East Coast after an oil rig explosion, a top executive of BP Plc (BP.L) said the disaster "will change the offshore industry forever around the globe."
Senator Benjamin Cardin told reporters that Kerry and Lieberman have modified the offshore oil drilling provisions of the bill that had been included to win Republican votes.
"It's my understanding there have been modifications; there is a much stronger protection for the coastal areas," said Cardin, who represents the East Coast state of Maryland, where there are worries about possible offshore drilling in neighboring Virginia.
Moves to expand oil drilling risk losing the support of some Democrats for the climate change bill, as do provisions that would help fund an expansion of the nuclear power industry.
Lou Hayden, a lobbyist for the American Petroleum Institute, which represents major U.S. oil firms, said prospects were poor for passage this year of a climate bill that some of API's members oppose.
"Quite frankly our consensus among our companies and our consultants is that we really don't see how it moves forward in an election year. I don't know changes they can make now can help; it has lost a lot of momentum by now."
Lieberman said that he and Kerry would have preferred to win back Graham's support. "But right now it's more important to just get the bill out, create the public discussion ... also to show the support that we have" in the Senate. (Additional reporting by Timothy Gardner and Jeff Mason; Editing by Eric Walsh)