Senate Minority Whip Trent Lott (R-Miss.) is vowing a Republican filibuster of legislation that would benefit union organizing, adding to the obstacles Democrats face in implementing the hotly contested proposal.

“It ain’t gonna happen,” Lott said in an interview.

Democrats, led by Sen. Edward Kennedy (D-Mass.), the chairman of the Senate Health, Education, Labor and Pensions Committee, are promising to fast-track a companion to a labor reform bill that recently passed out of the House.

The House voted on March 1 to pass the Employee Free Choice Act (H.R. 800). The legislation would authorize creation of a union if a majority of employees signed cards in favor of doing so. Union organizing elections are currently held by a secret-ballot vote.

However, Senate Republicans, including Lott, are pulling out all the stops to defeat its companion. “We are going to fight it all out,” including a possible filibuster, he told CongressNow. Opponents of the bill, including many business groups, argue that public ballots will lead to union intimidation of workers.

Republicans are confident that the bill does not have the support in the Senate to pass. But even if the bill does make it through, they are confident that Democrats will not have the numbers to override a threatened presidential veto.

Some lobbyists agree that prospects for the bill are dim. The legislation will not get any Republican votes, especially with such labor-friendly Republicans as former Sen. Ben Nighthorse Campbell (R-Colo.) having left office, one lobbyist said. If Majority Leader Harry Reid (D-Nev.) brings the bill to the floor, it will only serve a symbolic purpose, sending a message to unions — a core Democratic constituency — that the party is supporting their agenda, the source added.

The bill has been the subject of a fierce lobbying battle, with labor unions pushing the new Democratic majority to pass the bill as business groups put Members on notice that their vote will be watched closely.