As the White House weighs the latest emergency loan requests from General Motors (GM) and Chrysler, it’s quickly becoming apparent that the rescue of the Big Three auto makers could eclipse $100 billion -- more than five times the amount of loans they have already received.

Mark Zandi, who told Congress last year the bailout could ultimately cost as much as $125 billion, told FOX Business he stands by that forecast.

Zandi said he thinks lawmakers are aware of the enormous price tag but not necessarily the general public.

“I think they’re coming quickly to the realization it’s going to cost a lot of money. But everyone is becoming unnerved to these numbers,” said Zandi.

White House officials and restructuring experts continue to debate whether GM and privately held Chrysler should file for Chapter 11 bankruptcy protection in order to be in a better position to gain concessions from unions and bondholders.

“One way or the other taxpayers are unfortunately going to pay, whether they pay to nurse them through this period or in bankruptcy” that will result in a weaker economy, said Zandi.

A government-financed bankruptcy appears to be gaining some steam, as The Wall Street Journal reported Monday the Treasury Department is urging banks to line up $40 billion -- the largest bankruptcy loan ever -- in case a Chapter 11 filing is deemed necessary.

“I sense the attitude towards some type of bankruptcy restructuring -- either in Chapter 11 or some special flavor of bankruptcy… is softening both in Washington and in Detroit,” Paul Ingrassia, Pulitzer Prize winner and author, told FOX Business.

Based on one of President George W. Bush’s final acts, GM and Chrysler have already received $17.4 billion from the U.S. to stave off collapse. The auto makers’ financial arms -- GMAC and Chrysler Financial -- have received an additional $7.5 billion in loans. 

The price tag for the Big 3 rescue will only rise from here as GM and Chrysler last week asked for another $22 billion, Ford (F) could still need emergency loans and the auto makers have requested billions to retool their factories.

Of course, the eventual grand total will be heavily impacted by when the economy recovers. Given that the economic news has gotten significantly worse since Zandi testified last year, he said Detroit’s ability to maintain its 50% market share is “at risk.”

Zandi sees the cost of avoiding near-term bankruptcy jumping from $75 billion to $125 billion if the auto makers’ market share falls from 50% to 40%.  “At this point we’re closer to 50% than 40% but it’s still fragile,” said Zandi. “Obviously things are getting worse, not better.”

So far Ford hasn’t been forced to take any emergency funds but the auto maker has requested $11 billion in retooling loans.

“They’re obviously under severe stress that is intensifying. One can’t rule out the fact they could need help as well,” said Zandi.

The government may also be forced to help keep the parts suppliers afloat as the industry requested up to $25.5 billion to avoid collapse 

Experts are split on whether or not GM and Chrysler’s restructuring plans, which were released last week, go far enough.

GM pledged to cut 47,000 jobs, close five factories and consider eliminating up to four of its eight brands. Chrysler said it will cut its capacity by 100,000 units, slash 3,000 jobs and restructure $2 billion of its debt into stock.

The GM plan “is not really a measure that will get you where you need to go to make this company survive,” said Ingrassia.

Zandi was more optimistic, saying if GM and Chrysler “can follow through on what they laid forth [the plans have] a reasonable shot at succeeding.”

Washington will also continue to play a pivotal role in whether GM and Chrysler take the steps necessary to fix their business models.

“My sense is that if policymakers are able to put a bit more pressure on them, they will do enough to become viable again -- certainly at a big cost to taxpayers. That’s probably a better alternative to bankruptcy,” said Zandi.

Ultimately, Ingrassia said the White House should not give GM and Chrysler more money without a requirement for bankruptcy-type restructuring.

“Otherwise you are just going to keep throwing money at them,” said Ingrassia.