Senate Republicans blocked on Tuesday a bipartisan effort to pass a clean extension of the law authorizing the Federal Aviation Administration, a move that could have helped to end the partial closure of the agency and put 4,000 furloughed FAA employees back to work.

Sen. Barbara Boxer (D-Calif.) sought unanimous consent to pass the extension, which was sponsored by Senate Commerce Chairman Jay Rockefeller (D-W.Va.) and ranking member Kay Bailey Hutchison (R-Texas).

But Sen. Tom Coburn (R-Okla.) objected because he wants to make cuts to the Essential Air Service program, which provides subsidized air travel to rural communities. The fiscal hawk said he wants to restrict the subsidy to people who live 90 miles or more from major airports.

“I understand that we have placed people in difficult positions,” Coburn said. “But it’s us as a body, not individual Senators or parties, that have done that because we’ve failed to do our work.”

Coburn also pointed out that he had been assured by the office of Speaker John Boehner (R-Ohio) that the House had no plans to take up the extension. The chamber began its summer recess on Monday night, but it did not formally adjourn.

The FAA reauthorization has languished for more than seven years, and Congress has extended the current law 20 times.

But many Senate Democrats oppose an extension that the House passed July 20. It includes a provision that would cut about $16 million from the Essential Air Service, which would leave 13 airports out of the program, including those that are less than 90 miles from a hub airport and those getting subsidies exceeding more than $1,000 per passenger.

They also oppose language in a multi-year extension from the House that would make it more difficult for airline and rail workers to unionize.

The FAA has been partially shuttered since July 23 because of the standoff, resulting in the furlough of 4,000 FAA workers and the loss of at least 70,000 FAA-construction related jobs.

Coburn offered his own unanimous consent agreement to pass the House bill, which would then have gone to the president for his signature. Senate Majority Leader Harry Reid (D-Nev.), who was pushing to end the partial shutdown, said earlier in the day that he would be willing to accept the House extension.

But Boxer objected, and Democrats blamed Republicans for the impasse.

“Four thousand air travel employees are out of work and safety inspectors are working without pay because Republicans are playing reckless games with airline safety,” said Adam Jentleson, a spokesman for Reid. “Republicans are trying to jam through a policy that benefits the CEO of Delta airlines, and laying off thousands of air travel workers just because they are not getting their way.”

Reid and Democrats contend that the anti-union language in the House measure is meant to benefit Delta, which wants to stanch the unionizing activity of its workers.

“There is bipartisan agreement that we should keep air travel employees and safety inspectors on the payroll while we work out our policy differences, but we are being blocked by a handful of Republicans,” Jentleson said. “We should not let ideology interfere with making sure that Americans’ air travel runs as smoothly and safely as possible.”

Correction: Aug. 3, 2011

The article misstated what legislation contained language that would make it more difficult for airline and rail workers to unionize. That provision was contained in a multiyear Federal Aviation Administration reauthorization that the House passed.