Prospects that Congress will resolve a bitter deadlock over long-term federal funding for aviation this year are slim, Senate Commerce Committee Chairman John D. Rockefeller IV warned Monday.

“We cannot continue on this disastrous path, but we do stand on the precipice of losing another FAA reauthorization bill this year,” Rockefeller (D- W.Va.) said in addressing the Aero Club of Washington, an aviation industry group. “We’re willing to do what we have to do, but on the other side of the building there’s no movement and no give. Once again we are stalled.”

The congressional stalemate, which led to a shutdown of the Federal Aviation Administration this summer, comes at a critical hour. Airlines are reluctant to begin investing up to $10 billion in a revolutionary air traffic system without confidence that the FAA has long-term funding to develop the plan.

The issues that have stalled a compromise on bills earlier this year in the Senate and House affect a relative handful of the millions of Americans who will fly this year, and the primary hang-up is of interest to hardly any of them.

It is a dispute over a labor ruling that would make it easier for employees of Delta Air Lines to unionize. House Republicans are dead set on undoing a ruling by the National Mediation Board, which said that airline unionization efforts should be decided by a majority of those who vote. The ruling negated a long-standing rule that said eligible voters who opted not to vote would be counted as voting against unionization.

The NMB ruling is expected to have its most immediate impact on Delta, which has so far staved off union organizers.

“I am angry at the situation,” Rockefeller said. “I do not understand how this fixation with one airline can be seen as paramount [such] that the House would shut down the FAA to get its way, which they did.”

House Transportation Committee Chairman John L. Mica (R-Fla.) has said that Republicans would be willing to compromise if the Senate would agree to allow union decertification by a simple majority vote.

Rockefeller said he would take part in a bipartisan meeting Tuesday morning with three of his counterparts in the House and Senate.

“We will have almost nothing to say to each other,” he said.

The other issues holding up the bill have been the number of slots that should be allocated to airlines using Reagan National Airport, governing where those planes should be authorized to fly, and federal subsidies to provide regular airline service to rural airports.

“None of these issues is more important than the development of the next-generation traffic control system, not even close,” Rockefeller said. “Nevertheless, the small issues that divide us may ultimately dictate the outcome.”

Congress has approved 22 short-term funding extensions since the last funding bill expired in 2007. With budget cuts looming, Rockefeller said failure to pass a long-term FAA bill this year could prove catastrophic.

“If the FAA reauthorization does not pass soon, I believe it will be a long time before an FAA reauthorization will pass any Congress,” he said. “Congress may abandon regular FAA authorization bills altogether in favor of more discrete aviation legislation or just plain cuts. A lot of people are very much in favor of that.”