President George W. Bush's plan to cut $36 billion from Medicare ran into stiff opposition on Wednesday from dozens of his fellow Republicans in the House of Representatives.

The move creates doubts about getting Bush's 2007 budget through Congress -- and is another sign of growing tensions between the president and his fellow Republicans in Congress.

In another headache for Bush, a top Senate Republican said he was putting on the back burner the president's proposal to expand tax-free Health Savings Accounts, a major component of the administration's effort to reduce health care costs.

Bush proposed trimming $36 billion over five years -- and $105 billion over 10 -- from Medicare, the federal health plan for America's elderly, mostly by slowing payments to hospitals, nursing homes and similar health care providers.

The plan was immediately criticized by Democrats who are likely to make health spending an issue in the November congressional elections. More than 60 House Republicans now have come out in opposition as well.

"Hospitals are not just a health care safety net for their communities but also anchor local economies. They also must stand ready to respond to natural disasters, pandemic diseases and the threat of terrorism," the House Republicans wrote in a letter made public on Wednesday.

"Our hospitals are already stretching scarce resources to respond to the daily challenges of caring for all who come through their door. ... Now is not the time for further reductions," said the letter, written by Reps. John McHugh of New York and Jim Gerlach of Pennsylvania.

Their letter did not rule out all Medicare cuts, and it focused on hospitals. But it does suggest that any cuts should be more modest than Bush proposed and not greatly affect hospitals. It will also make it harder for House Republican leaders, also trying to satisfy conservatives who want to slash spending, to come up with a spending blueprint that can pass.

EARLIER CUTS

The proposed Medicare cuts would be in addition to $39 billion in cuts for health and other social programs recently enacted after a bitter congressional debate.

The Senate Budget Committee was trying to finish writing its version of a fiscal 2007 budget blueprint by Thursday with a full Senate debate expected next week. It has abandoned related spending legislation mandating more cuts to domestic entitlement programs such as Medicare and Medicaid.

"We didn't have the votes," Budget Committee Chairman Judd Gregg, a New Hampshire Republican, told reporters this week.

The House Budget Committee has not yet made enough progress to schedule a budget-writing session.

Senate Finance Committee Chairman Charles Grassley, an Iowa Republican, said at a hearing on health tax policy that he does not plan to advance the White House proposal to expand tax-free health savings accounts or HSAs. HSAs were not likely to win approval without a special budget process that protects legislation from procedural obstacles, and that is unlikely this year.

Bush proposed tax changes meant to expand HSAs, which allow people use pretax dollars for health care spending. The accounts are paired with insurance plans that cover catastrophic illnesses.

Democrats generally oppose HSAs, arguing that they would encourage employers to drop traditional coverage and would disproportionately help healthier and wealthier people.

Many Republicans say HSAs would make health care more affordable and enable people to spend more wisely.

Also on Wednesday the Senate Health, Education, Labor and Pensions Committee was working on legislation to allow small businesses to pool together to buy affordable insurance. Critics fault those plans because they would be exempt from many state regulations.

Similar legislation has repeatedly passed the House but faced opposition in the Senate.