The most lucrative job in Washington these days just might be health care lobbyist -- as prominent interest groups announce plans to pour millions of dollars into fighting over President Obama's efforts to create a universal health care system.

The White House has sought to curtail the role of lobbyists, but the heated public debate over Obama's health plan has made them very much a part of the legislative process.

The five largest private insurers and the trade group America's Health Insurance Plans spent a total of $6.4 million in the first quarter, an increase of more than $1 million from the same quarter last year. The industry is working to counter proposals endorsed by the White House that would offer a government health insurance option for millions of Americans.

The American Medical Association, the nation's largest physicians group, has its own formidable lobbying operation and said Thursday that it isn't sold on Obama's call for a public health plan, which could be a hurdle to his reform efforts.

The AMA is calling for a system that offers "affordable, high quality health insurance," its president, said Dr. Nancy Nielsen.

Nielsen stopped short of saying the AMA will lobby to block Obama's plan, but she made clear that the group "opposes any public plan that forces physicians to participate, expands the fiscally-challenged Medicare program or pays Medicare rates."

"The AMA is willing to consider other variations of a public plan that are currently under discussion in Congress," she said, including a federally chartered co-op health plan or a level playing field option for all plans.

Obama, who has pledged to bring down health care costs and extend coverage to 50 million uninsured Americans, said he wants a bill on his desk by October. He is expected to speak before the AMA Monday to lay out his agenda and address concerns from the group.

Meanwhile, lobbyists are furiously spending dollars either to block the proposal, which some have dubbed "socialist medicine," or to back Obama's agenda, which he says will make health insurance more affordable for millions of Americans.

"We're putting all of our resources behind advancing health reform," Robert Zirkelbach, a spokesman America's Health Care Plans -- AHIP -- told FOXNews.com.

Though Zirkelbach declined to release how much the lobbying firm has spent thus far, he said, "We're going to do everything we can to achieve reform."

"We strongly agree with the president that we need health care reform and we share his goal of providing every American with access to health care coverage," he said. "The current system is not acceptable."

Among other lobbying groups in the fight: Minnetonka, Minn.-based UnitedHealth Group Inc. has spent $1.5 million in the first quarter, up 34 percent from $1.1 million in the same quarter last year; Hartford, Conn.-based Aetna Inc. spent $809,793, up 41 percent from last year; and Indianapolis-based WellPoint Inc. and Louisville, Ky.-based Humana Inc. both saw first-quarter spending rise 16 percent to $1.2 million and $370,000, respectively.

Pfizer Inc., the world's biggest drugmaker, spent more than $6.1 million lobbying the government in the first quarter on health care reform, drug coverage provided under various government programs and other matters, according to a recent disclosure report.

Pfizer -- the maker of cholesterol fighter Lipitor, impotence pill Viagra and pain reliever Celebrex -- more than doubled its lobbying spending from a year ago. The company also spent nearly $3.3 million lobbying in the fourth quarter of 2008.

The Associated Press contributed to this report.