The House has opened debate on President Barack Obama's landmark health care overhaul that would extend insurance to tens of millions of Americans and enact dramatic changes to the country's medical system.
In the opening moments of debate, Democrats hailed the legislation as an advance for the nation's social fabric and a moral and economic imperative.
Republicans said it would be a government takeover of the health care system that would damage the economy and erode the doctor-patient relationship.
The vote planned for late Saturday was expected to be tight. Democratic leaders hoped a late-morning visit by Obama to Capitol Hill would push it over the edge.