WASHINGTON - President Barack Obama is trying to persuade a weary public and wavering Democrats to get behind his frantic, late-stage push on health care reform, while Republicans dig in and demand starting from scratch after a year's worth of work on the president's top domestic priority.

"Now, despite all the progress and improvements we've made, Republicans in Congress insist that the only acceptable course on health care is to start over. But you know what? The insurance companies aren't starting over," Obama said in his weekly radio and Internet address Saturday.

"I just met with some of them on Thursday, and they couldn't give me a straight answer as to why they keep arbitrarily and massively raising premiums -- by as much as 60 per cent in states like Illinois. If we do not act, they will continue to do this."

Republicans were not swayed.

"It's not too late: We can, and we must, stop this government takeover of health care," said Rep. Parker Griffith, a retired physician and a first-term congressman from Alabama who switched parties in December and delivered the Republican message.

The competing addresses underscored the urgency behind Obama's last-ditch push for immediate health care reform. Without a victory -- and quickly -- Democrats move into a fast-approaching election season without a major, tangible accomplishment that affects voters' pocketbooks. And with a chasm remaining between the two parties, Democrats considered passing the overhaul with votes just from their party.

That process would let the 59-member Senate Democratic caucus, including two independents, declare victory with a simple majority instead of a 60-vote supermajority usually needed to overcome procedural manoeuvrs to block final votes on legislation.

It also would allow Obama's team to get back to talking about the economy, which has shed more than 8 million jobs since the recession began.

Obama is pleading with Democrats to overcome divisions to seize a historic moment to remake the health care system during this election year. The White House wants to pass a health care overhaul and then campaign on it. At stake in the November election is control of Congress -- with races to fill 36 of 100 Senate seats and all 435 seats in the House of Representatives.

White House officials hope the immediate changes in the health overhaul would be enough to satisfy voters' expectations -- and Democratic lawmakers who were hardly unified in support of the plan.

If Democrats pass the plan, voters would find greater consumer protections and a ban on discriminating against customers with previous ailments. Small businesses would receive a tax credit this year, insurance companies would no longer be able to drop patients' coverage if they become sick, and plans would be required to offer free preventive care to customers. The U.S. is the only major industrialized country without universal health care coverage.

Griffith said leaders of the Democratic Party he left last year were missing the point.

"For them, health care reform has become less about the best reforms and more about what best fits their 'Washington knows best' mentality -- less about helping patients and more about scoring political points," he said. "This is no idle observation. I've witnessed it firsthand."