Updated

The biggest obstacle Democrats face in their efforts to overhaul the country's health care system may not come from conservatives or industry leaders. It may come from within their own party.

Sens. Ted Kennedy of Massachusetts and Max Baucus of Montana, who are spearheading the reform efforts, are trying to deter speculation fueled by media reports that they are at odds over a health care proposal.

Kennedy, who has maintained a low profile in recent months as he battles brain cancer, is returning to the spotlight to help advance a bill before the August recess. His bill, outlined in a policy overview, would guarantee universal access to health care, create a public insurance option and require individuals and employers to buy coverage. But that differs from what Baucus has been working on with the top Republican on his committee, Sen. Charles Grassley, who opposes the public insurance option.

Other details in Kennedy's plan may be hard for some to swallow: expanding the Children's Health Insurance Program to cover individuals up to 26-years old, up from 18; providing insurance subsidies on a sliding scale to families with incomes 500 percent above the poverty line, and offering a public insurance option that would pay providers more than Medicare rates.

On Saturday, Kennedy, chairman of the Health, Education, Labor and Pensions Committee, and Baucus, chairman of the Finance Committee, issued a joint statement expressing their commitment to finding common ground on health care legislation.

"For both of us, reforming the nation's health care system to cut cost, improve quality and provide affordable coverage remains the top priority on our two committees," they said in the statement. "We have worked together closely over many months and will continue to do so. We intend to ensure that our committees report similar and complementary legislation that can be quickly merged into one bill for consideration on the Senate floor before the August recess."

President Obama has made health care reform a centerpiece of his political agenda to address a system that is the most costly in the world but still leaves roughly 46 million Americans without insurance. It also lags other developed nations in indicators of healthcare quality, including life expectancy and infant mortality, according to studies.

Obama is pressing Congress to pass a bill by the end of this year. He has urged lawmakers to make sure any bill lowered costs, let American's choose their own doctor and health plan and ensured quality, affordable care for everyone.

"These are principles that I expect to see upheld in any comprehensive health care reform bill that's sent to my desk," Obama said this month.