Washington: The US Senate on Tuesday narrowly rejected 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.
Supporters of the long-delayed project, a top Republican energy priority, came up one vote short of the 60 needed for approval in the 100-member chamber.
Rejection of the $5.3-billion project, which became a political football in the aftermath of November`s midterm elections, sets up another likely showdown when the new Republican-controlled Congress convenes in January.
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 project due to concerns that it would harm the environment.
Republicans vowed they would bring the bill to another vote in early 2015.
"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," top Republican Senator Mitch McConnell said.
"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."
The vote is a victory for environmental groups and their supporters, including Boxer, the California senator who led Democratic opposition to the project.
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."
The failure relieves President Barack Obama -- at least for now -- of the potential headache of vetoing the measure, as he recently has signalled several times over the past week that he might do. 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 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, came down to the wire, with supporters spending the day scrambling for a final Democrat to sign on.
But with potential swing voters like independent Senator Angus King and Democratic stalwart Senator John Rockefeller announcing they would vote no, the bipartisan pro-Keystone coalition could not reach the finish line.
"Congress is not -- nor should it be -- in the business of legislating the approval or disapproval of a construction project," King said of the pipeline that would transport 830,000 barrels of oil per day from Alberta province to US refineries.Keystone`s progress is closely monitored in Canada, where government officials and builder TransCanada have said the project would provide an economic boon.
The State Department, which has authority over Keystone because of its international link, released a review in January finding that the project`s 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.
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 the midterms, 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, who is facing a December 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.