WASHINGTON — The Bush administration is expanding a government program to help homeowners head off foreclosure as it scrambles to counter Democratic calls for a broader federal housing rescue.

The plan would enable more low- to moderate-income homeowners to refinance into mortgages with monthly payments they can afford, while lenders would take a loss on the loans.

It is a more modest version of a concept Democrats have been pushing in recent days to respond to the mortgage mess, which would have the Federal Housing Administration back restructured loans for distressed borrowers. The administration's idea, however, would reach far fewer borrowers than the Democrats' proposal and would be financed by homeowners' mortgage insurance premiums rather than taxpayer dollars.

The plan would expand a program, known as FHASecure, that Democrats have argued has done too little for struggling homeowners and doesn't reach the vast majority of distressed borrowers.

"We believe that the reach of this program can and should be extended in a responsible way," FHA Commissioner Brian Montgomery said in testimony prepared for a House Financial Services hearing Wednesday on the housing crisis.

FHA Secure has already helped out nearly 150,000 borrowers, and with the expansion it expects to help a total of about 500,000 homeowners by the end of the year, said White House Press Secretary Dana Perino.

"The expansion will allow the program to insure loans for Americans who may have been late with a couple of payments and are facing interest rate resets, but who are otherwise reliably creditworthy — verifiable income, decent credit histories and they live in their homes," Perino said.

She said the proposal "is not a silver bullet that will solve all the problems in housing, but it will help some additional people stay in their homes and that's something the president wants to see."

In his statement, Montgomery raised serious concerns about a broader proposal drafted by Rep. Barney Frank, D-Mass., the Financial Services Committee chairman, that would have the FHA insure up to $300 billion in restructured loans for homeowners facing foreclosure.

He said the measure was an overly rigid approach that would put the government at inappropriate risk and allow the agency to insure excessively risky borrowers.

The Senate, meanwhile, is working to quickly pass a grab bag of measures aimed at helping homeowners and businesses weather the housing crisis.

Large tax breaks for homebuilders and credits for people who buy foreclosed properties, as well as $4 billion in grants for communities with the highest foreclosure rates to buy and rehabilitate foreclosed properties, were centerpieces of the bipartisan measure set for a Senate vote Wednesday.

Proponents call the plan an important first step in addressing the nation's economic woes, but some lawmakers in both parties are cool to the bill, which they say would do little to help people staring at foreclosures or bolster the shaky housing market. Its diverse critics include President Bush and House Speaker Nancy Pelosi, D-Calif., who want a measure more targeted to helping homeowners.

Rep. Charles Rangel, D-N.Y., chairman of the House Ways and Means Committee, scheduled a vote in his panel Wednesday on a rival plan that instead would steer tax breaks toward first-time home-buyers and investors in low-income rental housing. That bill likely will be paired with Frank's broader housing rescue package, expected to see a vote in May.

Frank was hearing from regulators and economists Wednesday on his plan. It would insert the government squarely into the middle of the mortgage mess, with taxpayer dollars at risk should homeowners default on the new loans. It would require lenders to write down large losses on distressed mortgages and help only those borrowers who could show that they were able to make payments on new loans.

The plan already is under fire from Republicans who characterize it as a massive government bailout.

House Minority Leader John Boehner, R-Ohio, said Congress should "work to help the innocent victims of the housing crisis, without providing a taxpayer-funded bailout to speculators, scam artists or recklessly irresponsible borrowers."