Washington ? The Senate cleared the last hurdle Friday to passing a housing rescue aimed at sparing hundreds of thousands of homeowners from foreclosure and bolstering troubled mortgage giants Fannie Mae and Freddie Mac.

The 80-13 test vote showed broad support for the election-year package and put it on track to pass the Senate by today. The White House says President Bush will sign it, having earlier dropped a threat to veto it over $3.9 billion in neighborhood grants.

The bill – regarded as the most significant housing legislation in a generation – is designed to help an estimated 400,000 homeowners escape foreclosure by letting them refinance into more affordable loans backed by the Federal Housing Administration.

It was set to clear Congress as a private company reported that the number of households facing the foreclosure process more than doubled in the second quarter of 2008 compared with a year ago. Irvine, Calif.-based RealtyTrac, Inc., said that 739,714 homes received at least one foreclosure-related notice during the quarter, or one in every 171 U.S. households.

“The American people can begin to see they’re going to get some relief and some help from their Congress,” said Sen. Christopher J. Dodd, D-Conn., the Banking Committee chairman.

The plan gives the Treasury Department power to spend unlimited amounts to prop up Fannie and Freddie, should they need it, to calm investor fears about their financial stability at a time of rising foreclosures and falling home values. Treasury Secretary Henry M. Paulson calls the authority a “backstop” that he has no intention of using.