Conservatives cheered the demise of the federal Export-Import Bank Tuesday and vowed to beat back efforts to revive it, even as business leaders and the White House issued dire warnings that letting the agency expire at midnight would hurt U.S. competitiveness globally.

"Ding Dong, the Ex-Im Bank is dead!" declared FreedomWorks, one of the outside groups responsible for transforming the bank from an obscure government lending institution into a conservative rallying cry.

"This is a critical blow to manufacturers," countered Aric Newhouse, a senior vice president at the National Association of Manufacturers, arguing that the bank plays a necessary role in underwriting loans to help foreign customers purchase U.S. goods.

The charter of the 81-year-old government agency expires at midnight Tuesday without congressional action, and with the House and Senate on recess for the July 4 holiday there was no chance of a last-minute reprieve. Supporters warn that billions of dollars in pending deals are at risk because of the failure to renew the bank's charter, something that's been done numerous times over the years with little to no controversy.

"Congress is taking a step backward," President Barack Obama argued in an opinion piece distributed by the White House Tuesday. "Other countries aren't going to just stop competing when Ex-Im lapses."

But although the Export-Import Bank will be unable to make new loans as of midnight, it will stay in business for the time being to service more than $100 billion in outstanding loans and guarantees, and no immediate layoffs or changes are planned, bank officials said. The bank is funded through Sept. 30.

Supporters are making plans to revive the bank in the coming weeks by attaching it to must-pass legislation to extend the highway trust fund. Senate Majority Leader Mitch McConnell, R-Ky., told The Associated Press this week that supporters of the bank have the votes to pass it and he will give them the opportunity to do so. Whether it could then get through the House is less certain, and conservative groups and lawmakers pledged to redouble their efforts to oppose it.

Sen. Marco Rubio, R-Fla., a candidate for president, warned Tuesday that the Export-Import Bank threatens to "rear its head once again" when Congress returns from recess next week, and said opponents must "remain vigilant."

"Ex-Im still benefits a few large politically connected corporations at the expense of all taxpayers," Rubio said on a conference call organized by the billionaire Koch brothers' Freedom Partners. "The only thing that's changed ... is the intensity of the grassroots effort on this critical issue and that's why their voice is going to be needed more than ever now."

Pressure from tea party-backed lawmakers and outside conservatives like the Koch brothers has pushed GOP congressional leaders and presidential candidates to line up against the bank, defying their traditional allies in the business community who support it.

That's led to bitter grumbling from some business leaders. Two business officials on a conference call Tuesday organized by the Exporters for Ex-Im Coalition, a group backed by the National Association of Manufacturers and others, attacked House Majority Leader Kevin McCarthy, R-Calif., in unusually personal terms for turning against the bank.

One of them, Don Nelson, president of California-based ProGauge Technologies, said he'd met with McCarthy personally to explain that his company that makes oil industry equipment will have to stop exporting if the Export-Import Bank is dissolved.

"Truth be told, he has zero experience or knowledge on the topic and yet he and other misguided congressmen portray they're experts on this topic and say the private sector can take over," Nelson said. "They really don't have a clue what they're doing or the damage they're going to inflict on small businesses in America by closing the Ex-Im bank."

McCarthy spokesman Matt Sparks disputed the criticism in a statement. "In the marketplace of ideas the best argument should win, and while the congressman understands the concerns of the bank's supporters, he believes the role of the bank is better suited for the private sector," Sparks said.