Keystone pipeline re

The lame-duck Congress has been in session a matter of hours, and the Keystone pipeline already is a political football.

Democratic Louisiana Sen. Mary Landrieu, facing a tough runoff election next month, on Wednesday called for a vote on a bill approving the long-delayed project -- in an apparent bid to flex her clout on Capitol Hill.

Moments later, her GOP challenger Rep. Bill Cassidy answered back by calling for a vote on a similar measure in the House.

The back-and-forth amounts to a continuation of their bitter Senate campaign, with one of the most controversial energy projects in America caught in the middle. The TransCanada-built pipeline, which would cross over an aquifer in Nebraska, has been held up for six years by environmental and other concerns. The Obama administration, under pressure from environmental groups, repeatedly has ordered reviews by the State Department.

Landrieu, who is thought to be trailing Cassidy ahead of their Dec. 6 runoff election, wants to deliver a win for the energy industry by pushing Keystone. The measure, which could be voted on Thursday, was one she co-sponsored with Sen. John Hoeven, R-N.D., back in May.

'We can pass the Keystone pipeline and answer the frustrations of the American people,' she said. 'So they could rest next and say, oh my gosh the senators of the United States of America have ears and they have brains and they have hearts and they heard what we said and we can do this.'

But the timing immediately raised Republican suspicions.

Cassidy noted that the House has passed pro-Keystone legislation eight times, and 'the Senate did not consider any of the eight.' After Landrieu called for a vote, Cassidy and GOP leaders in the House said they would also vote Thursday on a Cassidy-authored Keystone bill.

'I hope the Senate and the president do the right thing and pass this legislation creating thousands of jobs,' Cassidy said in a statement. 'After six years, it's time to build.'

The legislative tug-of-war came a day after aides first said that Senate Democrats were considering bringing the pipeline to a vote in order to boost Landrieu ahead of the runoff election. (The two rivals are heading to a runoff because neither got more than 50 percent of the vote last week.) The pipeline is a popular project in oil industry-heavy Louisiana, and Landrieu has touted her support of the pipeline and her tenure as chairwoman of the Senate energy committee in her campaign.

On the Senate floor on Wednesday, Landrieu insisted she was not trying to gain political points, and said she didn't even care if her name stayed on the bill.

'I didn't come here to see my name in lights,' she said. 'I came to fight for jobs for my state.'

She also seemed to take credit for Cassidy's House bill, calling it 'identical' to the legislation she co-sponsored.

Senate Republicans have pushed for the project to be approved for years, and backers of the project got a major win after Republicans took control of the Senate.

Landrieu is facing a tough battle to keep her job after nearly 20 years in office. A Real Clear Politics average of recent polls has the senator trailing her rival by nearly 5 points ahead of the election on Dec. 6.

Fox News' Kara Rowland, Chad Pergram and Mike Emanuel contributed to this report.