With emotions running high on both sides of the divisive debate over the Keystone XL pipeline, a new lawsuit from environmentalists and predictions of victory from the project's congressional supporters today lent a high-noon feel to the showdown over the $7 billion Canada-to-U.S. oil link.

As three green groups charged federal agencies with letting TransCanada Corp., the Alberta-based company behind the project, clear land and move endangered species in Nebraska to make way for the 1,700-plus-mile pipeline -- before its receipt of a final permit from the Obama administration -- pro-XL lawmakers vowed to ensure that conservationist critics do not derail its construction.

"The environmental community is trying to make oil sands product the new ANWR [Arctic National Wildlife Refuge]," Sen. Lindsey Graham (R-S.C.) said today at a forum hosted by Nelson Mullins, a firm where South Carolinian and former U.S. ambassador to Canada David Wilkins lobbies on behalf of Alberta-based fuel companies that would benefit from the XL line.

"That is misplaced, it will do lot of damage to energy policy in the U.S., and we're not going to let it happen," Graham added, telling attendees that he has spoken with Secretary of State Hillary Rodham Clinton "on multiple occasions" to ensure that "she understands the value of ... being able to purchase from our closest and best friend a product we desperately need."

The advocacy groups behind today's court challenge, the Center for Biological Diversity (CBD), Friends of the Earth and the Western Nebraska Resources Council, are part of a united green front that is pooling political and grassroots resources in a bid to stop Keystone XL.

The groups blast the pipeline as a guarantor of future U.S. dependence on emissions-heavy oil-sands crude as well as a safety risk to areas such as the Nebraska Sandhills, where sensitive land and species could suffer during leaks. The Sandhills lie at the heart of the new lawsuit, which alleges that the State Department and the Fish and Wildlife Service flouted the National Environmental Policy Act (NEPA) by allowing TransCanada to clear a 100-mile corridor in Nebraska "under the guise of" a research permit given to a contractor for the company.

"It's outrageous that TransCanada is already clearing the way for the Keystone XL pipeline before the public has had a chance to have its say and, indeed, before federal agencies have even said it can be built," CBD endangered species director Noah Greenwald said in a statement on the suit.

More legal action by environmental groups is likely to follow in the coming months, depending on how Clinton's department weighs in on a final permit for the pipeline. State gave an early thumbs-up to Keystone XL and its daily shipping capacity of more than 800,000 barrels of oil-sands crude in an August environmental review, but other factors -- from national security to economics -- are now in the mix ahead of an ultimate decision, expected before 2012 (Greenwire, Aug. 26).

Yet environmental groups blasted that August assessment from State as a whitewash of concerns that range from species in the Sandhills to refinery pollution in Texas, where the pipeline would terminate (see related story). Today's lawsuit is unlikely to be the last NEPA-related filing that seeks to block the pipeline as green advocates ratchet up pressure on President Obama to pull State's power over the project or risk their disengagement in the 2012 election.

'Defining issue'

Graham today met those warnings with one of his own. "This will be a defining issue in 2012, if the administration gives into the environmentalist position" and rejects the pipeline, he said, describing arguments about the higher carbon footprint of oil-sands crude as "esoteric" and unable "to sway most Americans."

American Petroleum Institute (API) President Jack Gerard, whose group has joined other oil, gas and business interests in countering environmentalists' XL messaging, also vowed today to overcome resistance from "a handful of shrill opponents" of the project.

Asked whether his group would consider aiding any legal effort to ensure its construction, Gerard said: "We'll clearly do our part to make sure the XL pipeline is approved."

That approval is hotly sought by congressional Republicans as well as oil-state and more conservative Democrats. One member of the latter camp, Rep. Gene Green (D-Texas), joined Graham today at the Nelson Mullins forum that also drew South Carolina Reps. Tim Scott (R), Jim Clyburn (D), and Mick Mulvaney (R).

Green touted the pipeline's importance to refineries in his district that are seeing a downturn in imported product, quipping that he spoke to Clinton about the XL link "before all the fire and smoke and everything else came up -- since then, it's been literally [talked of by some as] the end of the world if this pipeline gets built."

After that allusion to environmentalists' mounting campaign to derail the project, he added: "If this pipeline doesn't get built, it could be the end of domestic [gasoline] production, at least in our area."

Meanwhile, a liberal Democratic counterweight to Green came today from Rep. Earl Blumenauer (Ore.), who released a letter co-signed by five caucus colleagues that urges Clinton to deem "the current proposed route" for the pipeline unacceptable and cite NEPA in calling for more in-depth analysis of alternative paths for XL.

"Rather than acting as fair arbiters of TransCanada's application to build a massive pipeline across environmentally sensitive areas of the United States, State Department officials appear to have acted as little more than cheerleaders for the company's bid," the Democrats added.

Click here to read the environmentalists' lawsuit against the XL line.