General Motors Corp., the largest U.S. automaker, probably has weeks rather than months left before it runs out of cash without federal aid, said Jerome York, an adviser to billionaire Kirk Kerkorian and former GM board member.

Chief Executive Officer Rick Wagoner ''all but said'' at congressional hearings in the past two days that GM can't continue to operate until a new U.S. administration takes over in January, York said in a Bloomberg Television interview today.

GM, Ford Motor Co. and Chrysler LLC should develop a detailed plan for sustained operations and present it to Congress as a condition of receiving support, with ''chains'' rather than ''strings'' attached, York said.

U.S. lawmakers after hearing from Wagoner, Ford chief Alan Mulally and Chrysler CEO Robert Nardelli remain deadlocked on an auto-industry bailout. Democratic congressional leaders disagreed with Republicans and President George W. Bush's administration over how to provide $25 billion in aid to the three companies, with just two days left in Congress' lame-duck session.