WASHINGTON - The White House denied Wednesday it had given up wooing Republican support for President Barack Obama's embattled health care reform plan, following reports Democrats may go it alone.

"The president has said countless times he will work with anybody in any party that wants to work constructively on health care reform," said White House spokesman Robert Gibbs.

Expectations that the Democrats would fall back on their majorities in the House of Representatives and the Senate to pass the bill were fanned by several media reports late on Tuesday and early Wednesday.

The New York Times quoted White House chief of staff Rahm Emanuel as saying the Republican leadership had made a strategic decision to defeat health care reform, Obama's signature domestic initiative.

But Gibbs said Obama was committed to engaging with Republicans in pursuit of a bipartisan measure.

"There are still several more weeks to go in potential negotiations between Republicans and Democrats. I don't know why we would short-circuit any of that."

Obama would like to win some Republican support for his bid to cut health care costs, expand access and rein in insurance giants, in line with his vow to drain the partisan bile from Washington.

Republican votes may also give vulnerable lawmakers from conservative Democratic districts some cover to vote for the measure, or leeway to oppose it without endangering its chances of passing Congress.

Gibbs said he believed there were some Republicans still working in a "constructive" way to promote health care reform during the August congressional recess.

"We will get in a rocket and fly around the moon if that is what it takes to get everybody together and get an agreement," Gibbs said.

After spending last week repulsing Republican attacks on the health care reform drive, Obama is now facing a liberal backlash, following reports, denied by the White House, that he is prepared to drop a plan for a government-run entity or "public option" to compete with private insurance plans.

In a sign of an intensifying sales job the the president, Obama planned later Wednesday to address liberal religious leaders on the health care reform drive in a conference call.

Thursday, he has lined up a live online and telephone meeting with Organizing for America, the network of millions of grass roots supporters which emerged from his 2008 campaign infrastructure.

And the White House said that Obama would appear live to take listeners calls on the radio show of conservative commentator Michael Smerconish on Thursday.

Obama also faces mounting pressure from Democratic allies on his left flank, who had made it clear they will fight to preserve the "public option" and warned legislation without that element will fail.

Leaders of the 83-member Congressional Progressive Caucus of the House of Representatives sharply warned Health and Human Services Secretary Kathleen Sebelius in a letter Monday not to drop the public option.

"To take the public option off the table would be a grave error; passage in the House of Representatives depends upon inclusion of it," wrote Democratic Representatives Raul Grijalva, Lynn Woolsey, and Barbara Lee.

"The opportunity to improve access to healthcare is a onetime opportunity. Americans deserve reform that is real -- not smoke and mirrors. We cannot rely solely on the insurance companies' good faith efforts to provide for out constituents," they wrote.

But conservative Democrats are wary of the "public option" fearing a backlash from voters suspicious of the federal government.

And Kent Conrad, chairman of the Senate Budget Committee which is helping draft health care legislation, has warned there are not sufficient votes for the "public option" in the Senate.