WASHINGTON – When Congress returns from summer recess on Sept. 9, passing a health reform bill will be at the top of the agenda. And it won’t be easy, experts say.

In July, the House proposed America's Affordable Health Choices Act, said by House Speaker Nancy Pelosi (D-Calif.) to be geared toward the middle class and capable of lowering costs for consumers and businesses.

The bill would be paid for, in part, by a surtax of as much as 5.4 percent on Americans with annual incomes above $350,000 and would "put doctors, not insurance companies back in charge," Pelosi said.

House Republicans don't agree. Rep. Dave Reichert (R-Wash.) said the Democrats' proposed $1.1 trillion healthcare overhaul, with its public health plan option, would raise costs, reduce choices and allow government bureaucrats to interfere in the patient-doctor relationship.

The bill was developed and passed by the three House committees with jurisdiction over healthcare – Education and Labor, Ways and Means and Energy and Commerce – and awaits a full House vote this fall. Most House Democrats have pledged support, but some are concerned about the way the Senate is still struggling with a bill. Observers say this could cause some House Democrats to waver.

In the Senate, the Health, Education, Labor and Pensions Committee passed its version of the reform bill. But the final Senate committee with health jurisdiction, the Senate Finance Committee, hasn’t been able to find a compromise or enough votes to pass a bill, with a handful of Democrats joining the Republicans to oppose, among many things, the trillion-dollar price tag and a government-run plan option.

Large numbers of opponents to a government-run option at town halls across the country have concerned some Democrats, though most say the ruckus has been "staged" by Republicans.

With concerns over a bill passing the Senate, there has been some talk that Democrats may use a loophole for passing the bill by combining it with a federal budget bill. This would require only 51 Senate votes to pass, rather than 60. The White House has not welcomed such a plan because President Barack Obama would like to have bipartisan support for health reform.

Pelosi has indicated the House will likely use its majority to pass a bill, with or without Republican support.