AFP - US President Barack Obama is sharpening his rhetoric and raising the stakes as he confronts pressure to restore his battered authority with Wednesday's address to Congress on health reform.
  
Obama is facing calls to finally set out concrete proposals on his top domestic priority after a vitriolic summer marked by shrill attacks by Republican critics and his own diminishing popularity.
  
In unusually inflammatory language, Obama told labor unionists in Ohio on Monday that critics were lying about his proposals, and dipped into an armory of campaign-style rhetoric not deployed since his triumphant White House race.
  
"You've heard all the lies. I've got a question for all those folks: what are you going to do? What's your answer? What's your solution? And you know what? They don't have one," the president said.
  
"Their answer is to do nothing."
  
Obama's rare speech to a joint session of Congress is about much more than his effort to cut costs for those who have private insurance and to cover the 46 million Americans who are not insured.
  
With the young president's political brand under severe strain, the outcome of the health care struggle has the potential to shape his chances of passing an ambitious agenda and authority on pressing foreign policy questions.
  
It comes at a time when Obama needs maximum political leverage for his effort to restore the crippled US economy, to pass global warming legislation and to answer tough questions about sending more troops to Afghanistan.
  
While coming out firing, the president must also muster an intricate behind-the-scenes effort to broker compromise in Congress for a health care bill that can satisfy his own political requirements.
  
Signaling a newly urgent bid to drive the debate to a conclusion, Obama added on Monday: "It's time to act and get this thing done."
  
Obama was due to meet fellow Democratic power brokers, House of Representatives speaker Nancy Pelosi and Senate Majority Leader Harry Reid at the White House on Tuesday to discuss tactics.
  
So far, Obama has declined to spell out a concrete plan for reform, a fact that may have spurred his critics. But spokesman Robert Gibbs hinted that could change.
  
"(Viewers will) leave that speech knowing exactly where the president stands, exactly what he thinks we have to do to get health care reform done this year," Gibbs said on ABC television on Sunday.
  
The White House signaled at the weekend that Obama would make the case for a "public option" -- a government-run entity to compete with private health insurance providers in the complicated US health care market.
  
But aides did not commit to vetoing any bill that did not include such a plan, leaving open the chance for compromise, but also dismaying some core supporters.
  
The public option is beloved of Obama's Democratic political base, and some lawmakers, especially in the House, have warned they will not vote for a reform that does not include it.
  
But Republicans have successfully seized on the idea to play on the ingrained American fear of overweening federal government, to claim Obama is bent on a takeover of the lives of ordinary Americans.
  
In the Senate, Democratic leaders have argued there is no support for the public option and some moderate Democratic lawmakers appear skittish at backing Obama's plans in a volatile political environment.
  
On Monday, details emerged from the Senate Finance Committee of a possible compromise, replacing the public option with a network of non-profit cooperatives to compete with private insurers, according to media reports.
  
The plan also reportedly aims to cut costs cited as a major roadblock by reform opponents, by offering younger healthier Americans with protection only against catastrophic illness and expanding government coverage for poor people.
  
Any plans eventually passed through the House and the Senate would need to be reconciled -- a process that could pose a political headache for the White House -- before being sent to Obama for his signature.
  
The flaming debate during August, which has seen lawmakers assailed by angry voters at town hall meetings, has contributed to a slump in Obama's own political authority.
  
The president's latest Gallup approval ratings stood at 52 percent on Tuesday, up from a low of 50 percent but down from a high of 69 percent in the euphoric early days of his presidency in February.
  
Should he fall below 50 percent before November, it would represent the second fastest drop of an elected president to below-majority approval since World War II, behind Bill Clinton (four months).