Congressional leaders and administration officials have agreed on legislation to have the U.S. government spend up to $700 billion on a financial market rescue.

Negotiators said at about 12:30 a.m. Sunday they had come to terms on a proposal to authorize Treasury Secretary Henry Paulson to put together one of the most comprehensive government interventions in U.S. business since the Great Depression, The Washington Post reported.

The officials did not provide full details of the plan, which would allow the Treasury Department to purchase mortgage-backed assets from distressed firms in a move intended to reopen clogged credit markets.

Saturday's negotiations were largely focused on how to protect U.S. taxpayers from getting stuck with the plan's cost, the newspaper said. Democrats pushed for a fee, to be levied on the financial services sector after five years if the government had not yet fully recovered the cost of implementing the bailout.

"We believe that the taxpayer should not be left holding the bag at the end of the day, and we've proposed a way to address that," said Rep. Chris Van Hollen, D-Md.