More than two dozen trade associations are preparing to give the White House public support for raising the debt ceiling.

The ad hoc coalition — which includes the U.S. Chamber of Commerce, the Financial Services Forum and the National Association of Manufacturers — has been circulating a letter downtown that will be sent as early as next week to Senate and House leaders urging Congress to act on Treasury Secretary Timothy Geithner’s request to raise the federal debt limit.

A draft of the letter obtained by Roll Call warns, “We strongly agree with Secretary Geithner that the failure of Congress to increase the statutory debt limit in a timely fashion could have a significant and long-lasting negative impact on the U.S. economy.”

Despite the call for raising the debt ceiling, the groups also say they “remain extremely concerned” about the federal debt and budget deficits.

“Tough calls on U.S. spending must be made as part of a debate about the budget and we agree with Secretary Geithner that restoring balance to our fiscal position will ‘require that the government spend less and spend more wisely,’” they write.

The letter comes as House Republicans are continuing to maintain that there must be spending cuts attached to a vote to raise the debt ceiling. It’s unclear so far what Republicans will be able to get President Barack Obama and Congressional Democrats to agree to.

However, industry’s decision to publicly endorse a debt ceiling increase may provide cover for Republicans who campaigned against raising the debt limit to vote for the final package.

The groups aren’t stopping their campaign once the letter is sent to Capitol Hill. The chamber also plans to use its extensive grass-roots network once Congress sets a date for a vote and when it is apparent what deal is cut, according to a spokeswoman. NAM declined to discuss the letter.

The ad hoc coalition is not the only effort among K Streeters. The Information Technology Industry Council, which has not signed on to the trade group letter, has been moving ahead with its own push on the debt limit.

The group’s top lobbyist, Ralph Hellmann, said, “We are focused instead on providing concrete policy proposal to lawmakers on how to reduce spending or raise revenues. Both sides of the debate are looking for proposals that can be part of a deficit reduction, debt limit package.”

The tech group has been meeting with members of the “gang of six” — a bipartisan group of Senators trying to reach a broad deficit reduction deal — including Sens. Mark Warner (D-Va.) and Mike Crapo (R-Idaho) and House Budget Committee staff, among others.

“Congress is going to raise the debt limit by July, so the real fight will be over what is attached to it,” Hellmann said. “That’s where we will focus our attention.”