WASHINGTON — The Bush administration yesterday raised the price tag on its emergency plan to revive the U.S. financial system, asking Congress for $700 billion to get bad mortgage assets off the books of troubled financial institutions in a bid to end the U.S. economy's most serious financial crisis since the Great Depression.

The amount is staggering, and would likely hamper the ability of the next president to pursue new domestic programs without major tax increases.

It also comes at a precarious time when the country is facing increases in spending as the nation's 75 million baby-boomers begin to reach retirement age in 2010.

As part of its rescue plan, the administration also asked Congress to raise the nation's debt ceiling from its current level of $10.6 trillion to $11.3 trillion.

Members of Congress and administration officials were locked in negotiations over the proposed legislation, with both sides saying they would like a final bill ready before markets open tomorrow.

A person familiar with the talks said that there had been major disagreements over who would pay for the expected cost and how.

Congressional negotiators also want the bill to spell out more clearly who would supervise the Treasury's purchase of the bad debts; the administration's proposal simply assigns the responsibility to Treasury Secretary Henry Paulson and gives him authority to hire whatever people or outside firms he needs to do the job.

"We're going to work with Congress to get a bill done quickly," President Bush said at the White House. Without discussing specifics, he said, "This is a big package because it was a big problem."

The proposal is a mere three pages long, but it gives sweeping powers to the government to dispense gigantic sums of taxpayer dollars in a program that would be sheltered from court review.

The measure sets no limit on how long Treasury could hold the assets, which must have been issued before Sept. 17. But the goal would be to sell them after housing prices recover and to earn back much of the money.

"It's a rather brief bill with a lot of money," said Sen. Chris Dodd, D-Conn., the Banking Committee chairman. "We understand the importance of the anticipation in the markets, but we also know that what we're doing is going to have consequences for decades to come.

"There's not a second act to this — we've got to get this right."

NO HOMEOWNER HELP

Some Democrats were critical that the proposal didn't include relief for average mortgage holders.

"This is a good foundation of a plan that can stabilize markets quickly," New York Democratic Sen. Chuck Schumer, chairman of Congress' Joint Economic Committee, said in a statement. "But it includes no visible protection for taxpayers or homeowners. We look forward to talking to Treasury to see what, if anything, they have in mind in these two areas."

The top Republican in the House also voiced reservations about the plan. "We need to do everything possible to protect the taxpayers from the consequences of a broken Washington," Rep. John A. Boehner of Ohio said in a statement.

But he also warned against efforts to load up the legislation with additional provisions that would require debate. "Efforts to exploit this crisis for political leverage or partisan quid pro quo will only delay the economic stability that families, seniors, and small businesses deserve," he said.

Senior administration officials meanwhile pressed their counterparts in Japan, Germany, the United Kingdom and elsewhere to establish similar programs to rescue their own troubled firms in what would be an unprecedented bailout of the worldwide financial system.

The move comes in recognition that complex interconnections among financial institutions have created a global crisis that the United States cannot solve alone.

An official at the Bank of England who spoke on condition of anonymity said the bank has been in constant contact with its U.S. counterparts to try to win a "global response to a global problem." The European Central Bank declined comment.

CANDIDATES STAY QUIET

Neither presidential candidate took a position on the proposal. GOP nominee John McCain said he was awaiting specifics and any changes by Congress.

Democratic rival Barack Obama used the party's weekly radio address to call for help for Main Street as well as Wall Street.

Their language reflected a tricky balance that politicians in both parties are trying to strike, just six weeks before Election Day: Back a plan that doles out hundreds of billions to companies that made bad bets and still identify with the plight of middle-class voters.

Paulson announced the plan to buy up bad mortgages on Friday. The proposal circulated yesterday added some detail, but still left unclear precisely how the government intended to take control of the bad loans or where the money would come from to pay for them.

Most precise was the expected cost — $700 billion. But the remainder of the program would be left to Paulson to design, the proposed legislation said.

DETAILS OF PLAN

Under the proposed law, the Treasury Department would be authorized to purchase "mortgage-related assets from any financial institution having its headquarters in the United States."

That provision would seem to anticipate the possible purchase of individual mortgages as well as the complicated mortgage-backed securities at the heart of the current crisis.

It also would exclude foreign-based banks and hedge funds from taking part in the program, though U.S.-based hedge funds, which invest on behalf of the ultra wealthy, would be able to participate.

Under the draft, Paulson, or his successor, would be required to report to Congress after three months, and then on a semi-annual basis until the assets had all been sold or liquidated.

The draft makes no mention of how the process of buying bad assets would happen, but it is widely believed to involve what's called a reverse auction process.

In a regular auction, a seller asks a starting price and bids go upwards. In a reverse auction, however, the buyer — in this case the government agency — asks for a price and sellers decide whether or not they will sell at the price and could even bid the price downwards.

The Associated Press and The Washington Post contributed to this report.