Steven Rattner, co-leader of the task force overseeing federal aid to General Motors and Chrysler, said the companies may need "considerably" more than the requested $21.6 billion to survive.

In a report by Bloomberg News, Rattner, interviewed for "Political Capital with Al Hunt" said, "What they've asked for depends on them achieving plans that are somewhat ambitious. Like all management teams, they tend to take a reasonably, slightly perhaps, optimistic view of their business. So it could be more. I can't rule that out."

Rattner, a financier, is a senior adviser to the auto panel along with Ron Bloom, former assistant to the president of the United Steelworkers union.

Speaking specifically to Chrysler's condition, Rattner said, "We have not made a determination on whether they could exist on a stand-alone basis, but we do find their idea of partnership with Fiat a worthy idea to consider."

He characterized Chrysler's Robert Nardelli and GM CEO Rick Wagoner as "good guys really trying hard to run those companies," adding, "I have nothing bad to say about them."

At the same time, however, Rattner did point out, "The government cannot solve everybody's problems, and we need for the bondholders to become part of this in a constructive way."