By Victoria McGrane. Politico.

Treasury Secretary Timothy Geithner met with the heads of several business trade associations earlier this week, asking for their support as he pushes Congress to raise the cap on how much the nation can borrow.

The meeting shows that the Obama administration is worried that the perennial task of raising the limit on the national debt could become a real political problem — especially since lawmakers have gotten an earful from angry constituents about government spending this August. Raising the debt limit has become a fairly routine task in recent history — under both Republican and Democratic administrations — but with polls showing Americans increasingly concerned about deficits, the vote is a little trickier right now.

Geithner sent a letter to congressional leaders last week asking them to quickly raise the current $12.1 trillion debt limit, warning that it could be hit as early as October. Congress last upped the debt limit in February when it passed the $787 billion stimulus package.

And the House already took the first step toward raising it again, approving an increase in the debt limit in April as part of its 2010 budget resolution, leaving just the Senate to act.

Attendees at the Wednesday trade association meeting with Geithner included Bruce Josten, top lobbyist with the U.S. Chamber of Commerce; John Engler, head of National Association of Manufacturers; Rob Nichols, president and COO of the Financial Services Forum; and Gerald Howard, president and CEO of the National Association of Homebuilders, according to sources familiar with the meeting.

Geithner discussed his request to Congress and wanted to know where the business groups were, said Josten. The leaders said they were happy to support the request.

“I think every biz group has always supported raising the debt limit; there’s not much choice,” Josten told POLITICO.

Indeed, a failure to increase the debt limit would essentially push the federal government to default on its debts.

“This action is needed to maintain confidence in the full faith and credit of the U.S. government and prevent uncertainty that would hinder our economic recovery,” Financial Services Roundtable President and CEO Steve Bartlett said in a Friday letter to House Speaker Nancy Pelosi (D-Calif.) and Senate Majority Leader Harry Reid (D-Nev.).

“Inaction would undermine investor confidence in our financial markets, both at home and abroad,” he said, urging the leaders to “move quickly” before the current ceiling is hit.

Business leaders are working on a joint letter, as well.