A mortgage rescue to help hundreds of thousands of struggling homeowners avoid foreclosure and get more affordable, safer loans passed the Senate overwhelmingly Friday, but it faces a bumpy road amid continuing turmoil in the housing market.

The 63-5 vote reflected a keen interest by Democrats and Republicans to send election-year help to distressed homeowners with economic issues topping voters' concerns.

The plan lets homeowners buckling under mortgage payments they can't afford keep their homes and get more affordable mortgages backed by the Federal Housing Administration. Banks that agreed to take substantial losses on those distressed loans could avoid costly foreclosures and be assured of recovering at least some money.

The new program would let the FHA insure as much as $300 billion in new mortgages, helping an estimated 400,000 homeowners.

It still faces challenges, however, with the House planning to rewrite key details and the White House threatening a veto without major changes.

"It's not the final stop, but it is a major stop in getting this bill done," said Sen. Christopher Dodd, D-Conn., chairman of the Banking Committee. "For those who said this Congress cannot come together in a bipartisan fashion to do something responsible about housing, this bill does that."

Rep. Barney Frank, D-Mass., the Financial Services Committee chairman and an architect of the bill, says the few but significant revisions House leaders are seeking could be made in as little as one week.

Dodd said he was expecting minor "tweaks" that could be dealt with quickly.

But key players are bracing for intense negotiations to resolve the differences. They hope to smooth over disputes with the White House at the same time, with an eye toward producing a bill President Bush could sign later this month.

The White House Friday renewed its warning that Bush would veto the Senate-passed bill without revisions, citing $3.9 billion in the measure for buying and rehabilitating foreclosed properties it said would help lenders, not homeowners.

The measure includes a long-sought modernization of the FHA and would create a new regulator and tighter controls on Fannie Mae and Freddie Mac, the government-sponsored mortgage giants. It also would provide $14.5 billion in housing tax breaks, including a credit of up to $8,000 for first-time home buyers.

Democrats are divided over important elements of the plan, including limits on loans the FHA may insure and Fannie Mae and Freddie Mac may buy. The Senate measure sets them at $625,000, while House leaders — including Speaker Nancy Pelosi, D-Calif. — want the cap as high as $730,000.

House leaders also oppose the immediate effective date of the Senate plan, preferring to phase in the new regulations for Fannie Mae and Freddie Mac over six months.

"We'd have a hard time agreeing to that," Dodd told reporters Friday. He called a Capitol Hill news conference to dispel fears about the financial health of Fannie Mae and Freddie Mac as their stocks plummeted on reports that the government was considering taking over one or both of them.

Another key point of dispute is the funding in the Senate measure for buying and fixing foreclosed properties. The House's band of conservative "Blue Dog" Democrats oppose the money, arguing that it would swell the deficit unless paired with cuts or tax increases to cover the cost.

But many Democrats, particularly members of the Congressional Black Caucus, are fighting to keep the funding, which they say will help prevent the communities hardest hit by the housing crisis from sliding into blight.

"There are people who tell me to ignore" that threat, Frank said in a statement Friday. "But there is too much that is important in this bill, and it has already been too long delayed by procedural problems in the Senate, for us to risk the further delay involved in a veto."

He said he was working to find a way to shift the funds to a must-pass spending bill that would be approved before lawmakers scatter for the year in September.

Dana Perino, Bush's spokeswoman, said the money should be stripped out of the measure "so that they can get a housing bill to the president that he could sign right away."

Sen. Barack Obama, D-Ill., the presumptive presidential nominee, said Bush should drop his opposition to the housing plan and other Democratic efforts to ease economic pain.

"I call on the administration to support this bill along with a second emergency stimulus package to jumpstart the economy and build on this important start to advance more rigorous measures to protect homeowners from foreclosure."

With the administration scrambling to tamp down on investor fears about Fannie Mae and Freddie Mac, Perino called the new regulations in the measure for the two mortgage giants its "most important feature."

Lawmakers and the Bush administration agree on the central concept behind the housing package: allowing the government to backstop new mortgages for struggling homeowners.

To make it more palatable to Republicans, the Senate measure would take responsibility for any losses away from taxpayers and instead cover them by diverting a newly created affordable housing fund drawn from Fannie Mae and Freddie Mac profits.