They ran against debt. They swore and swore again that they’d cut up the nation’s credit card.

But now the 87 freshmen House Republicans are facing intense pressure from administration officials and even some natural allies on why they should — indeed, why they must — vote to allow the federal government to go even deeper into debt.

Financial industry executives, business leaders and Treasury Department officials are visiting the freshmen in their offices, briefing them in small groups and even cornering them at dinner parties. It’s all part of a behind-the-scenes campaign to school congressional newcomers in the economic stakes of Washington’s next big fiscal fight: over the debt ceiling.

The freshman class that gave Republicans the House majority will be a critical voting bloc in the looming clash over whether to raise the amount of money the government can borrow to keep it from defaulting on its loans.

“It is the big vote for all of us,” said Rep. James Lankford (R-Okla.). “I don’t think there’s been a week that I’ve been here where we’ve not had some kind of conversation with somebody dealing with debt ceiling issues.”

Like many in his class, Lankford had no prior experience in government. He was an evangelical youth-camp director before running for Congress last year as a fiscal conservative.

“All of us who are private citizens study the debt and can see it from a distance,” he said. “But when you get here and you get into the facts and into the weeds, it’s worse than you ever thought.”

The nation is expected to hit its current $14.3 trillion debt limit by mid-May. Treasury Secretary Timothy F. Geithner has said he could take emergency measures to buy time until July 8, but if no action were taken by then, the government would fall into default.

When Congress returns from its two-week spring recess on May 2, the debt limit will take center stage. But congressional leaders have signaled that it will be part of a broader spending deal. It could take several weeks, at a minimum, for Democrats and Republicans to reach an agreement.

Broad repercussions

Economists say failure to raise the debt ceiling would lead to cascading repercussions that would damage the United States’ creditworthiness and spark a debt crisis just as the country is recovering from the recession. Weeks of uncertainty about whether the ceiling will be raised could also cause havoc in financial markets, financial executives said.

Unlike many other nations, the United States limits its debt by congressional authority. And although raising the cap is one of the least popular votes that legislators take, they traditionally approve it when the issue comes up every few years.

But industry executives fear that this year could be different. The public scrutiny on spending issues is intense, and many congressional Republicans, under the watchful eye of tea party activists, have been loath to do anything that even appears like it could lead to more spending.

Industry officials said they have been warning lawmakers that a failure to act would reverberate not only through the bond markets, but across America. The government would no longer be able to pay for its commitments, such as Medicare and Social Security.

The officials said they try to make clear to lawmakers that raising the debt limit does not spur new spending. Instead, it enables the government to pay off maturing debt, or spending obligations already made.

And, they point out, if the nation goes into default, its borrowing costs would spike.

“We say: ‘Guys, if we breach it, if we default on our debt, it would make it even harder to pay it back because of the interest costs. And we know that’s not your goal, so just FYI,’ ” said one financial industry executive who, like some others interviewed, spoke on the condition of anonymity to recall private conversations with lawmakers.

Members of the Financial Services Forum — which represents the chief executives of 20 of the nation’s largest financial institutions — the U.S. Chamber of Commerce and other industry groups have fanned out across Capitol Hill to press lawmakers.

In some cases, lawmakers have been visited by community bankers and local business leaders from their districts — to put a friendly face on the lobbying effort and to underscore the point that it’s not just Wall Street, but also Main Street that would take the hit.

And when they see lawmakers at trade gatherings or dinner parties, Wall Street chief executives seek them out: “Hey, Congressman, I know you have to do what you need to do, but this debt ceiling vote is coming up, and I just want to take 10 seconds and talk about the economic consequences,” one executive said, describing conversations he and others have had.

Boehner on board

The Financial Services Forum, including Jamie Dimon, chief executive of JP Morgan Chase, sat down this month with House Speaker John A. Boehner (R-Ohio) with an urgent plea to act.

Privately, Boehner has been reassuring industry executives that his leadership team believes that raising the debt limit is “the responsible thing to do,” but that any increase must be accompanied by broad spending cuts and budgetary reforms, according to a GOP leadership aide.

The speaker reiterated that position last Wednesday in a one-hour closed-door meeting with Republican freshmen. Although a few dozen new lawmakers said in their campaigns that they would never vote to raise the debt ceiling, many in the class seem open to Boehner’s position.

Geithner and his deputies have also been tutoring lawmakers. The secretary met privately with members of the Senate Finance Committee last week. Treasury officials have written personal letters to legislators as well as blog items explaining the nuances of the issue.

Appearing Sunday on “Meet the Press,” Geithner said Republican congressional leaders told him and President Obama on Wednesday that they “recognize we can’t play around with this.”

“If you allow people to start to doubt whether the United States of America will meet its obligations, that would be catastrophic,” Geithner said.

Bruce Josten, the Chamber of Commerce’s top government affairs executive, said he has met with dozens of lawmakers on the debt ceiling and brings charts with him.

“If you’re a new member of Congress, how the hell would you know all of this?” Josten said.

There is an irony in Josten personally seeking support from the politicians that the Chamber spent more than $30 million last year helping to elect.

“We’re never going to have everybody, on whatever side of the aisle you want to at the time, vote with the Chamber,” Josten said.

‘Listening sessions’

Many Republican freshmen said they welcome what they have come to call “listening sessions.”

“I’m trying to be, like everybody else, a student of the broad spectrum of information,” said Rep. Patrick Meehan (Pa.).

Added Rep. Diane Black (Tenn.): “I’m somebody that loves to study.”

But Rep. Mo Brooks (Ala.) seemed to take offense to the outreach.

“There’s no need for someone to communicate to me about the adverse effect,” he said. “I have an economics degree, highest honors, from Duke University.”

“I believe every congressman by now knows the adverse effect of not raising the debt ceiling,” Brooks added. “That really is not the issue. The issue is what is being done to avert a federal government bankruptcy. As bad as not raising the debt ceiling might be, a federal government bankruptcy is worse. We have two bad choices to choose from, both of which are calamitous.”