President Barack Obama will tell Congress on Wednesday the time for bickering is over and call for quick action on a comprehensive healthcare overhaul that would dramatically transform the U.S. insurance market and health system.

In excerpts of his high-stakes, nationally televised speech to the U.S. Congress scheduled for 8 p.m. EDT (0000 GMT), Obama says lawmakers are closer to the goal of reform than we have ever been and issued a warning to critics.

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 said in the excerpts. If you misrepresent what's in the plan, we will call you out.

Obama hopes his speech will rejuvenate his flagging push for an overhaul of the $2.5 trillion healthcare system, which has bogged down in Congress and driven down his approval ratings amid a flood of criticism.

Instead of honest debate, we have seen scare tactics, Obama said of the volleys of criticism aimed at his plan in recent months.

The excerpts include a series of concrete proposals he said should be included in any final bill passed by Congress, including creation of an insurance exchange where individuals and small businesses could shop for policies.

Obama said he would prohibit insurers from dropping coverage for sick patients and capping coverage in a year or lifetime, would place a limit on out-of-pocket expenses, and require insurers to cover routine check-ups.

Now is the season for action. Now is when we must bring the best ideas of both parties together, and show the American people that we can still do what we were sent here to do, Obama said. Now is the time to deliver on health care.

In the Senate, months of bipartisan Finance Committee talks by the so-called Gang of Six negotiators moved into the final stages earlier in the day as the panel's Democratic chairman, Max Baucus, said it was time to proceed with or without Republicans.

CLASH OVER PUBLIC OPTION

Baucus told reporters he would push ahead with a bill next week modeled after proposals he distributed recently to members. That plan would levy a fee on insurers to help pay for coverage but would not include a government-run health insurance option, which he said cannot pass the Senate.

Baucus's plan also includes sweeping insurance market changes. It would tax insurance companies on their most expensive healthcare policies and offer tax credits to individuals and families to help offset the cost of premiums.

Three committees in the House of Representatives and one other Senate panel have completed work on a healthcare bill, leaving the Senate Finance Committee as the final hurdle before each chamber can take up the issue.

Obama is seeking a comprehensive healthcare overhaul that would cut costs, improve care, regulate insurers and expand coverage to more than 46 million uninsured Americans.

But Republicans have balked at the total cost, questioned Obama's pledge that the plan would not increase government debt and called some of the proposals a first step to a government takeover of healthcare.

Moderate and liberal Democrats, meanwhile, have clashed over the government-run public option Obama has backed.

Critics say the option would hurt insurance companies and give the government too broad a role in the industry. But liberal Democrats say it is crucial to fostering increased competition and they will not support a plan without it.

Obama has signaled he supports the government-run option but it is not essential to a final bill.

In a bid to win Republican support, White House spokesman Robert Gibbs said Obama would address reform of medical malpractice lawsuits, which Republicans blame for raising medical costs.

The president will talk about meaningful malpractice reform tonight. What I hope that does is cause Republicans to understand that we're close to getting something truly significant done for the American people, Gibbs said on Fox Morning News.

Obama hopes the speech can help him reclaim control of the debate on his top domestic priority after critics used a month-long August break for Congress to launch a wave of attacks on the healthcare plans.

The failure of the healthcare initiative could sharply weaken Obama less than a year into his presidency, endangering the remainder of his agenda from climate change to immigration reform and putting Democrats at risk in congressional elections next year.

Democratic President Bill Clinton's dramatic blowout on healthcare reform in 1994 led Democrats to lose power in both chambers of Congress in a landslide defeat later that year.

Shares of top health insurers, volatile as the healthcare debate gathers steam, were slightly higher in afternoon trade ahead of Obama's speech. Shares of the S&P Managed Health Care stock index were up about 1.8 percent while the Morgan Stanley Healthcare Payor stock index was up about 2 percent.

(Additional reporting by Patricia Zengerle, Steve Holland, Susan Cornwell, Donna Smith, Ross Colvin; editing by Jackie Frank)

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