WASHINGTON — A House Republican Tuesday offered a much narrower housing rescue bill than the $300 billion program Democrats are pushing.

The measure by Alabama Rep. Spencer Bachus, the top Financial Services Committee Republican, expands a Bush administration program that allows some struggling homeowners with subprime loans to refinance into more affordable, government-backed mortgages.

It would reach far fewer borrowers than an overhaul by Rep. Barney Frank, D-Mass., the panel chairman, aimed at heading off as many as 1 million foreclosures. Frank plans a committee vote Thursday on his bill , which is expected to move through the House in early May.

Frank has been working behind the scenes to draw bipartisan support for his measure, which has two Republican co-sponsors.

Lawmakers in both parties and President Bush have embraced its central concept: expanding the Federal Housing Administration, the Depression-era mortgage insurer, to help financially strapped homeowners who otherwise wouldn't qualify for government-backed loans refinance into cheaper fixed-rate mortgages.

The two parties are divided, however, over how to achieve that goal, and particularly on who — and how many — should benefit. Those differences reflect a more fundamental dispute over how substantial the government's role should be in stepping in to help struggling homeowners and stabilize the chaotic housing market.

"Some of the other legislative proposals would require taxpayers to subsidize the costs resulting from bad decisions made by some lenders, investors and borrowers. That's unfair," Bachus said in a statement.

He called his bill "the best strategy for addressing the problem and avoiding spreading the cost to innocent taxpayers."

The measure includes several initiatives that have bipartisan support, including an overhaul of the FHA, new regulations for Fannie Mae and Freddie Mac, the government-sponsored mortgage financiers and guarantors, and steps to protect homeowners from fraudulent or unscrupulous lending practices.

It also includes a provision, likely to be a part of any housing aid bill, that would shield mortgage holders from legal liability if they take a loss to allow a borrower to refinance into a more affordable loan. That's designed to address a fear among those who bundle mortgages into securities that investors will sue them if they change the terms of the loans.

Republicans and some conservative-leaning Democrats are reluctant to back any legislation that appears to bail out irresponsible homeowners and lenders, but with the economy slumping, foreclosure rates skyrocketing, and lawmakers nervously anticipating their re-election contests in November, congressional leaders and Bush administration officials are searching for a housing deal.

First, though, they will have to agree on the scope of any rescue package.

The Democratic bill would allow the FHA to take on up to $300 billion in new loans. The cost to the government would be a small fraction of that, however, depending on how many homeowners defaulted on their new loans and what their homes were worth at the time.

Frank's measure is also under fire from liberal groups, who say it could help some troubled borrowers, but would be inadequate to help tens of thousands facing foreclosure right now. The groups wrote to lawmakers Tuesday urging them to back a more aggressive bill that would let judges modify mortgages — including the amount owed, interest rates and fees — in bankruptcy proceedings.

The labor, civil rights and consumer organizations wrote that their support for any foreclosure prevention bill "will hinge on the inclusion of" the bankruptcy provision.

A similar proposal was defeated in the Senate this month. Both Frank and House Speaker Nancy Pelosi, D-Calif., have said they back the measure, but suggested it has little chance of making it through Congress.