A handful of lawmakers are accusing General Motors of misleading the public by continuing to claim as part of its advertising blitz that the auto giant has repaid its government loans "in full."

General Motors has been running ads on all the major networks claiming the company repaid its $6.7 billion U.S. government loan "with interest five years ahead of the original schedule." General Motors Company CEO Ed Whitacre can be seen in the ad walking through an auto plant as he touts the company's progress.

But lawmakers, and even the inspector general for the bailout fund GM borrowed from, point out that General Motors only repaid the bailout money by dipping into a separate pot of bailout money. They say the company did not actually use its own earnings to make the early payment and are questioning why executives are making such a big deal out of it.

"The hype is not the reality," Sen. Charles Grassley, R-Iowa, wrote in a column on FoxNews.com over the weekend. "It is far from clear how GM and the Obama administration could honestly say, much less trumpet in prime time television ads, that GM repaid its TARP (Troubled Asset Relief Program) loans in any meaningful way."

Grassley wrote a letter last week to Treasury Secretary Timothy Geithner expressing his concerns and asking for more information about why the company was allowed to use bailout money to repay bailout money.

The $6.7 billion is also just a fraction of the $52 billion General Motors received in government aid. Grassley said lawmakers are being told government losses on GM are expected to exceed $30 billion.

The TARP inspector general, Neil Barofsky, bluntly told the Senate Finance Committee during a hearing last week that the repayment "is just other TARP money" and lawmakers should not "exaggerate" the feat.

"It sounds like they're kind of like taking money out of one pocket and putting it in the other to do that," Sen. Tom Carper, D-Del., said at the hearing.

Sen. Richard Shelby, R-Ala., expressed similar concerns Sunday on NBC's "Meet the Press," saying it's "misleading" for the administration to claim the company has paid back its loans.

The GM ad could potentially land the company in trouble with the Federal Trade Commission over its truth-in-advertising laws, which prohibit ads that are "likely to mislead consumers."

The FTC would not comment on the specific GM ad.

General Motors admits that the company is repaying the loan with other government money, but says a year ago "nobody thought we'd be able to pay this back."