The Obama administration has more than a month left on its legal clock for ruling on the Keystone XL oil pipeline, but Republicans and their allies in industry already are preparing to pressure the White House throughout the spring and beyond.

Congressional Republicans are mulling legislative strategies that would nullify a presidential rejection of the $7 billion pipeline, should the State Department deny a permit to the Canada-to-U.S. project by the Feb. 21 deadline set by last month's payroll tax-cut deal. The top lobbyist for the U.S. Chamber of Commerce, whose president today implored the White House to approve the oil line, signaled that his group would back that GOP effort to keep the project alive through 2012.

"If there are viable ways to get it done" through legislation that would end-around an Obama veto of Keystone XL, the U.S. Chamber would lend its support, Executive Vice President Bruce Josten told reporters today.

Sen. John Hoeven of North Dakota is among the Republicans already working on plans to push the pipeline, which Josten described as the "number one energy issue" on the U.S. Chamber's agenda. While the GOP and business groups continue to clamor for the president to approve Keystone XL, which would ship more than 750,000 barrels of Canadian oil-sands crude to Gulf Coast refineries each day, few are willing to predict that last month's 60-day deadline would force Obama to sign off.

"There are two basic options -- you override the president or you go around the president," said a Senate GOP aide who spoke on condition of anonymity to address the ever-shifting politics of the debate.

"Both options are geared towards doing what he refuses to do, but both options could be structured in many different ways. The core is, there's not dissension. We're all aiming at the same goal."

The GOP aide dismissed the prospects of another two-month window for Obama to re-evaluate the pipeline, noting that "if the president has rejected it, there's no reason to think he'd give a different answer given another 60 days."

White House spokesman Josh Earnest today gave credence to that argument against a second 60-day deadline by noting that the pipeline's sponsor, Alberta-based TransCanada Corp., has yet to settle on an alternative route for the pipeline that skirts the sensitive Nebraska Sandhills region.

"[T]hat sort of underscores the difficulty of evaluating and affirming this project within that 60-day window, considering that there's not even a route for that pipeline that's under consideration at this point," Earnest told reporters.

Environmentalists who oppose the pipeline and its emissions-heavy oil-sands crude hope to see the administration deny a permit by Feb. 21, though they do not expect that ruling to dampen industry and GOP enthusiasm for the project. Natural Resources Defense Council President Frances Beinecke greeted the U.S. Chamber's pro-XL push today by accusing it and TransCanada of imposing "a Faustian bargain" on voters.

"Rather than bringing us prosperity, it will leave us with a legacy of poisoned lands and waters," Beinecke said in a statement calling oil company estimates of 20,000 jobs created by the pipeline inflated. "All for, at most, 100 permanent jobs?"