WISHINGTON: President Barack Obama urged Congress to set aside differences and work with him to overhaul the US health care system, delivering one of the most crucial speeches of his tenure.

Obama looked to seize the momentum on an issue that has divided fellow Democrats, energised opposition Republicans and contributed to the decline in the president’s once-soaring popularity.

The nationally televised speech before

a joint session of

Congress on Wednesday night was a political tour de force. To the public, he offered assurances that his plan would provide more security and more health care choices, while offering coverage to people who cannot now afford it.

To Republicans, he offered a hand to work together and pledged not to raise the government’s deficit. Yet for Democrats who want him to be more assertive, he lashed out at opponents who he accused of using scare tactics and lies to bring down the plan - and his presidency.

“To this date, the health care debate has looked like a tennis match between leaders in Congress, with the president sort of watching as it goes back and forth,” said Robert Blendon, a public opinion expert at the Harvard School of Public Health. “He’s taken control of this issue for now, and into the future it looks like there’s a plan, and he’s leading it.” Obama said, “I will not waste time with those who have made the calculation that it’s better politics to kill this plan than improve it.” He appealed to emotions, unveiling a letter from Edward Kennedy, the respected Democratic senator who died last month. In the letter, delivered posthumously, Kennedy expressed confidence that the overhaul would pass this year. Kennedy’s widow, Vicki, was in the chamber’s visitor’s gallery next to first lady Michelle Obama.

And Obama returned to the soaring political rhetoric that marked his presidential campaign.

“We did not come to fear the future. We came here to shape it,” he told lawmakers.

It is unclear if Obama persuaded any Republicans. In keeping with tradition, most sat silently or offered polite applause during the speech.

But in an unusual outburst, one Republican congressman, Joe Wilson of South Carolina, shouted out “You lie” when the president said illegal immigrants would not benefit from his proposals.

Health care has become the definitive issue for Obama, just nine months after he took office amid enormous expectations at home and abroad. His success or failure may

determine whether he

has the political clout to press ahead on issues

like climate change, arms control and the Afghanistan war. It is also likely to shape next year’s congressional elections.

The US is the only developed country without a universal programme of health care coverage.