WASHINGTON - The U.S. Senate rejected by a single vote Tuesday a bill that would have approved construction of the Keystone XL pipeline to bring crude oil to Gulf coast refineries from Canada's controversial tar sands.
Rejection of the $5.3 billion project came by the narrowest of margins and Republicans immediately vowed to approve the bill early in 2015 when the new Congress convenes with them in control of the next Senate.
Tuesday's vote relieves President Barack Obama -- at least for now -- of the potential headache of vetoing the measure, as he recently has signaled several times over the past week that he might do.
Supporters of the long-delayed project, a top Republican energy priority that has become a political football, came up one vote short of the 60 needed for approval in the 100-member chamber.
Many of the 45 Republicans who supported the bill, as well as some of the 14 Democrats who voted with them, described Keystone XL as a "no-brainer" that would generate thousands of jobs and improve American energy independence.
But critics, led by Senate Democrat Barbara Boxer, fiercely oppose the initiative over concerns that it would harm the environment.
Top Republican Senator Mitch McConnell said afterwards: "Senate Democrats once again stood in the way of a shovel-ready jobs project that would help thousands of Americans find work -- a remarkable stance after an election in which the American people sent a clear message to Congress, to approve serious policies.
"But once the 114th Congress convenes, the Senate will act again on this important legislation, and I look forward to the new Republican majority taking up and passing the Keystone jobs bill early in the New Year."
TransCanada, the company behind the pipeline, was similarly buoyant.
"We will continue to push for reason over gridlock, common sense over symbolism and solid science over rhetoric to approve Keystone XL and unlock its benefits for America," said CEO Russ Girling.
The rejection was a victory for environmental groups and their supporters, including Boxer, the California senator who led Democratic opposition to the pipeline.
Boxer, who warned of tar sand "poison" and "misery" afflicting American communities, stood on the Senate floor before a photograph of Chinese men wearing face masks under a gray haze.
"I remember the days in Los Angeles when the air looked like this," Boxer said. "I don't want it to look like what it looks like in China."
After the vote she said the bill's opponents "stood up for what is right -- protecting the health of families and the health of the planet."
Congressional Republicans have long pushed the Obama administration to lift its hold on the corporate-funded project, which remains under extended review some six years after permit requests were submitted.
The pipeline easily passed the Republican-controlled House of Representatives last week, as it has several times before.
The 59-41 Senate vote, the most contentious action in the chamber since Republicans roared to victory in the midterm elections earlier this month, came down to the wire, with supporters scrambling in vain for a final Democrat to sign on.
"Congress is not -- nor should it be -- in the business of legislating the approval or disapproval of a construction project," independent Senator Angus King said of the pipeline that would transport 830,000 barrels of oil per day from Alberta province to U.S. refineries.
Keystone's progress is closely monitored in Canada, where government officials and TransCanada have said the project would provide an economic boon.
The U.S. State Department, which has authority over Keystone because of its international link, released a review in January finding that carbon emissions would not be significant.
Obama has said he would only approve Keystone if it was shown to have minimal carbon emissions impact.
Critics argue that tar sand bitumen is some of the world's dirtiest oil.
But Republicans tout Keystone's generation of 40,000 temporary construction jobs. The State Department says only 35 permanent jobs will result.
Republicans gained at least seven Senate seats in their midterm romp, and when the new Congress convenes with McConnell at the helm in the Senate, they should have votes to pass Keystone.
The vote marked disaster for Keystone's main Democratic backer, Senator Mary Landrieu, the Senate Energy Committee chair who is facing a tough Dec. 6 runoff in Louisiana -- where she wants to be seen as breaking Washington gridlock.
Her Republican challenger, Congressman Bill Cassidy, introduced the parallel legislation that passed in the House.
The Republican National Committee rushed to gain some political mileage from the bill's failure, dubbing Landrieu "the energy chairman who still can't deliver Keystone."
Copyright Agence France-Presse, 2014