U.S. Senate Republicans inserted a rider on the planned Keystone XL oil pipeline from Canada into a transportation bill. A similar measure in the Republican-led House of Representatives strips authority away from the president on the pipeline.
Bill McKibben, founder of advocacy group 350.org, said his campaign in opposition to the Senate measure was signed by more than 500,000 people.
"Anyone who thought environmentalists were graying into irrelevance was wrong," he said in a statement.
Canadian pipeline company TransCanada wants to build Keystone XL to transit oil from tar sands projects in Alberta to refineries along the southern U.S. coast. Critics say Alberta crude is the dirtiest type of oil.
U.S. President Barack Obama denied TransCanada's permit earlier this year, citing an "arbitrary" deadline imposed by House Republicans in an earlier measure that extended payroll tax benefits.
"Americans don't want this oil, they don't want this risk and they don't want this political circus," Sierra Club Executive Director Michael Brune said in a statement.
Neither of the Republican measures is likely to pass through the Democratic-controlled Senate.