WASHINGTON — President Barack Obama and his top allies in the Congress worked Tuesday to map the way to enacting a sweeping overhaul of US health care by his annual marquee State of the Union speech, now weeks away.

Obama and the Democratic leaders of the Senate and House of Representatives were to discuss their final drive to pass the legislation, his top domestic priority, in talks at the White House set for 5:45 pm (2245 GMT).

The high-stakes discussions, at the dawn of a mid-term election year expected to see an erosion of the Democrats' House majority, aimed to chart the best way for the two chambers to reconcile their rival versions of the bill and approve a final compromise that the president could sign into law.

Both bills aim to extend health care coverage to some 31 million Americans out of the 36 million who currently lack it, while banning abusive health insurance practices and curbing skyrocketing US medical costs.

Passage would hand Obama and congressional Democrats a huge victory ahead of November elections that, if history is any guide, are likely to result in sizeable Republican gains in Congress.

With Republicans locked in unyielding opposition to the plan, Obama and his top legislative allies looked for ways to tamp down bitter intra-Democratic feuds that still clouded the fate of the legislation.

A headline battle looms over the provision of a government-backed "public option" to compete with private insurers -- a core component of the House version that Senators stripped from their less expansive bill.

Another potential obstacle is the House bill's tougher restrictions on federal funds subsidizing abortions: While pro-choice lawmakers denounce the limits, some centrist Democrats say they will withhold support without them.

Democratic House Speaker Nancy Pelosi was to meet first with Democratic committee chiefs in the House, amid an insurrection on the party's left-flank at the Senate's watered-down version of the bill.

Later, Pelosi and Democratic House Majority Leader Steny Hoyer were to attend the White House talks in person while Democratic Senate Majority Leader Harry Reid and his deputy, Senator Dick Durbin, were to join by telephone.

Democrats say they want final passage before Obama's State of the Union speech, which Pelosi has suggested could slide to early February from its typical late January date.

The House approved its version of the bill on November 7. The Senate adopted its version December 24.

According to media reports, Democrats may look to blunt Republican delaying tactics by skirting the traditional "conference" in which formally appointed delegates from each chamber meet to work out a final compromise.

Instead, key lawmakers and top White House officials would put together a final plan from the House and Senate version in informal talks sometimes known as "ping-pong" because the process can include the two chambers sending bills to each other until a final compromise is achieved.

Democrats have virtually no margin for error: The Senate's Christmas Eve vote rallied exactly the 60 votes needed to pass the bill, and some centrists have said they will oppose any major changes.

The United States is the world's richest nation but the only industrialized democracy that does not provide health care coverage to all of its citizens.

As a nation, the United States spends more than double what Britain, France and Germany do per person on health care.

But it lags behind other countries in life expectancy and infant mortality, according to the Organization for Economic Cooperation and Development (OECD).