The U.S. Senate on Wednesday failed to override President Barack Obama's recent veto of legislation approving the Keystone XL tar sands pipeline project.

The 62-37 vote fell just five votes short of the two-thirds majority needed to nullify the presidential veto.

Eight Democrats—the very same lawmakers who voted to approve the $8 billion pipeline project in January—voted to override the veto. They are: Sens. Joe Manchin (W.Va.), Heidi Heitkamp (N.D.), Mark Warner (Va.), Claire McCaskill (Mo.), Bob Casey (Pa.), Michael Bennet (Colo.), Tom Carper (Del.) and Jon Tester (Mont.). Indiana Democrat Joe Donnelly, who also backs the pipeline, missed the vote.

Failure to override the veto does not mean that the Keystone project is no longer a threat, environmental advocates warned on Wednesday afternoon after the vote.

In a reference to a recent stunt pulled by Republican Sen. James Inhofe (Okla.), during which he brandished a snowball on the Senate floor as evidence against climate change, 350.org U.S. communications manager Karthik Ganapathy said in a statement: "This vote does to Keystone XL what Jim Inhofe's snowball does to the overwhelming consensus on climate change: absolutely nothing."

"Congress has known from the beginning this bill would be dead on arrival—a fact even Denier-in-Chief Inhofe acknowledged when he said last week that Big Oil simply doesn't have the votes to override," Ganapathy continued. "Keystone XL has always been President Obama's decision, today does nothing to change that, and we're confident the President will do right by our climate and reject the pipeline once and for all."

According to The Hill, undeterred proponents of the pipeline vowed to attach its approval to an upcoming transportation bill or include it in a broader energy package.