Washington (CNN) -- President Barack Obama and Transportation Secretary Ray LaHood on Wednesday urged Congress to immediately pass a temporary funding measure for the Federal Aviation Administration to put nearly 4,000 federal employees back to work and restart more than 200 airport construction projects.
The Democratic-led Senate went on its summer recess Tuesday without approving what would have been the 21st short-term funding extension for the FAA. The Republican-led House previously passed a short-term extension, but included some changes opposed by Democrats.
In addition to workers being forced on temporary furlough, failure to extend funding for the FAA prevents collection of federal taxes on airline tickets that total $30 million a day. If the dispute continues until Congress returns in September, the federal government will be out more than $1 billion in revenue.
The FAA has been partially shut down for more than a week, but LaHood emphasized that flying remains safe despite the dispute. He had a direct message for Congress: "Leave your vacations just for a couple of hours" and return to work to "help your friends and neighbors get back to work."
LaHood, a former Republican congressman serving in the Obama administration, also said: "This is why people shake their heads when they think about Congress."
Obama called the impasse "a lose-lose-lose situation" that could be "easily solved," something he expects to happen before the end of the week.
"Congress has decided to play some politics with it and as a consequence they left town without getting this extension done," Obama said.
On one hand, the dispute involves language in the House proposal that would reduce or kill subsidies to rural airports, specifically targeting some in Nevada, Montana and New Mexico -- three states with influential Democratic senators.
However, a larger dispute behind the scenes also is a cause for the inaction. Republicans oppose a recent National Mediation Board decision backed by Democrats that makes it easier for airline employees to unionize.
The board's ruling made passage of a vote to unionize dependent on getting more than 50% support of those voting. For example, if a company has 1,000 workers but only 200 take part in the vote to unionize, the rule change would require 101 "yes" votes for it to pass.
Under old rules, more than 50 percent of all workers eligible to vote -- or 501 "yes" votes-- would have been required for it to pass. Workers who didn't cast ballots were counted as having voted "no", making it more difficult for supporters to succeed.
Sen. Orrin Hatch, R-Utah, told CNN on Wednesday he blocked a short-term compromise bid proposed by Democratic and Republican colleagues because of the organized labor issue.
At a news conference Wednesday, top Senate Democrats blamed Republicans for the work stoppage.
"This issue has nothing to do with essential air services (at rural airports) and everything to do with a labor dispute between airlines and the American worker," said Senate Majority Leader Harry Reid, D-Nevada.
In response, Rep. John Mica, the Florida Republican who chairs the House Transportation committee, said Senate Democrats have only themselves to blame.
"Senate Democrats had a House-passed FAA extension before them for two weeks but chose to do nothing," Mica said.
CNNMoney's Jennifer Liberto and Charles Riley and CNN's Tom Cohen, Ted Barrett and Mike M. Ahlers contributed to this report.