Washington ? The Bush administration asked Congress on Saturday for the power to buy $700 billion in toxic assets clogging the financial system and threatening the economy as negotiations began on the largest bailout since the Great Depression.

The rescue plan would give Washington broad authority to purchase bad mortgage-related assets from U.S. financial institutions for the next two years. It does not specify which institutions qualify or what, if anything, the government would get in return for the unprecedented infusion.

Democrats are pressing to require that the plan help more strapped borrowers stay in their homes and to condition the bailout on new limits on executive compensation.

Congressional aides and administration officials are working through the weekend to fill in the details of the proposal. The White House hoped for a deal with Congress by the time markets opened Monday; top lawmakers say they would push to enact the plan as early as the coming week.

“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.

“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.”

Lawmakers digesting the eye-popping cost and searching for specifics voiced concerns that the proposal offers no help for struggling homeowners or safeguards for taxpayers’ money.

The government must stabilize the financial system “because if we don’t, it will have a tremendous impact on American consumers, homeowners, taxpayers and the rest,” House Speaker Nancy Pelosi, D-Calif., said in San Francisco.

But, she added, “We cannot deal with this unless this bailout helps families stay in their homes.”

Senate Majority Leader Harry Reid, D-Nev., said “we cannot allow ourselves to be in denial about the threat now facing the world economy. From all indications, that threat is real, and the consequences of inaction could be catastrophic. Every single American has a stake in preventing a global financial meltdown.”

The proposal would raise the statutory limit on the national debt from $10.6 trillion to $11.3 trillion to make room for the massive rescue.