The bitter dispute over a union organizing effort that has crippled behind-the-scene efforts to restore funding for the Federal Aviation Administration spilled onto the Senate floor Wednesday.

By the time a brief but intense exchange in the normally civil Senate ended, Republicans had been accused of putting the interests of a single company — Delta Air Lines — ahead of public safety and middle-class wage earners. Democrats had been vilified as carrying the water for “big labor.”

The confrontation ended without any resolution of the stalemate that has left the FAA without funding authority since midnight Friday, a situation resulting in the furlough of 4,000 employees and the shutdown of airport construction projects nationwide.

The debate, however, brought to the fore the issue that has stalled a long-term funding bill for the agency and ultimately led to the collapse of efforts to extend funding at current levels until September.

The dispute involves the labor law that governs unionization efforts at airlines. Those efforts have been covered by the Railway Labor Act, under which eligible voters who don’t participate in a union election are counted as voting against unionization. That is at odds with the National Labor Relations Act, which says that votes to unionize are decided by a majority of those who participate.

Two years ago, the National Mediation Board said airline organizing efforts should be decided by a simple majority of votes cast. When the House passed a major FAA reauthorization bill this year it included a provision to nullify the board’s decision.

Inability to get the Senate to agree to that provision has frustrated House Transportation Chairman John L. Mica (R-Fla), who inserted an unrelated but equally controversial provision in the short-term funding extension in hopes that it would spur the Senate to a resolution on the larger bill.

Instead, it brought an angry John D. Rockefeller IV (D-W.Va.) to the Senate floor Wednesday.

“We are inflicting real pain on very real people,” said Rockefeller, chairman of the Senate Commerce Committee. “People are suffering. Small businesses are hurting.

Rockefeller said Delta had successfully staved off four attempts at unionization. When Rockefeller moved for expedited passage of an FAA extension without a disputed provision regarding service to three rural airports, Sen. Orrin G. Hatch (R-Utah) blocked the move.

“I share . . . Chairman Mica’s frustration that favors to organized labor have overshadowed the prospect for long-term FAA reauthorization,” Hatch said. “The House bill would merely undo a big partisan favor done at the behest of big labor. The House bill does not create a new hurdle to unionization. Instead, it restores the long-standing ability of airline employes to make decisions for themselves.”

On Wednesday, Rockefeller and several other Senate Democrats, including Mark Warner of Virginia, introduced legislation that would allow the furloughed workers to return to the job while the dispute plays out. The bill would permit the FAA to draw on the Aviation Trust Fund to pay the workers, who would be entitled to back pay.

“This will allow the agency to end the furlough and put them in the best position for when we achieve a full FAA extension,” Rockefeller said.