The House of Representatives is set to vote on a bill to approve the controversial Keystone XL oil pipeline.
The move comes as Democratic Senator Mary Landrieu has pushed for a similar vote in the Senate as she fights a runoff campaign for her seat.
The 875-mile (1,408km) pipeline would carry tar sands oil from Alberta, Canada, to the US state of Nebraska where it joins pipes running to Texas.
President Barack Obama could find the approved bill on his desk next week.
The White House has not directly threatened a veto of the legislation if it passes both chambers.
But spokesman Josh Earnest said Mr Obama takes a “dim view” of legislative efforts to force action.
The project has been a political football between Republicans and other supporters, who say it will create much needed jobs, and many Democrats and environmentalists, who warn the pipeline will add to carbon emissions and contribute to global warming.
A state department report raised no major environmental objections in February, but the final recommendation was delayed amid a court battle over the project in Nebraska.
The state department is involved in the permitting decision because the pipeline would cross an international border.
The Keystone XL pipeline aims to carry some 830,000 barrels of heavy crude a day from the fields in Alberta to Nebraska.
The oil would then be transported on existing pipes to refineries in Texas. The southern section of the project was finished last year.
A vote on the project in the Republican-controlled House of Representatives is expected to pass on Thursday.
A Senate vote is expected on Tuesday, and would rely on several Democrats, including Ms Landrieu who supports the project, to pass – as the new, Republican-controlled Senate will not be sworn-in until January.