House Speaker Thomas Foley said Friday that although congressional and White House bargainers are near a $500 billion budget deal, disputes remain that leave wide-scale slashes in federal programs looming for Monday.

"There are some remaining issues that are very difficult," said Foley, D-Wash.Negotiators, still divided over whether to impose new taxes on the wealthy and over other issues, planned to meet through the weekend in hopes of agreeing to a package. Congress planned a rare Sunday session to deal with the fiscal crisis.

More than four months of talks have brought tentative agreements to cut defense and domestic programs and raise the government's take on items ranging from gasoline to Medicare premiums, officials familiar with the talks said Thursday.