As health care reform takes shape in the House and Senate and shows signs of veering decidedly left, business lobbyists are considering joining their Republican allies and mounting a public relations offensive to put the brakes on President Barack Obama’s overhaul plans.

Advocates for health insurance companies, hospitals, provider groups and employers have so far been engaged in a marriage of convenience, hoping that by maintaining radio silence in exchange for a seat at the negotiating table they could influence the process and obtain a reform bill to their liking.

But as legislative details have emerged in recent days and suggested the business community could be stuck with costly mandates and a government-run, public plan option, lobbying groups are preparing to step up their opposition messaging.

“It is surprising to me the degree to which the stakeholders have complied when so much is at stake,— one health care lobbyist said Monday. “At what point does the silence end?—

When the business community finally gets around to raising its voice over the Democrats’ plans for health reform — as seems likely given Obama’s push for the public plan option and the strong possibility that employer-mandates will be proposed to help pay for the overhaul — they risk being shut out of the negotiating process by Senate Finance Chairman Max Baucus (D-Mont.).

Baucus, whose committee is scheduled to mark up its health care bill later this month, has previously warned lobbyists to hold their tongues regarding those objectionable proposals, or they would not be invited back to the negotiating table.

On Monday, a senior Senate Democratic aide affirmed Baucus’ previous warning, while also trying to calm nerves by contending that a long process remains between now and the Oct. 15 deadline Obama has demanded for passage of a health care reform bill.

“Do you really want to be zeroed out of the process?— this senior aide asked, rhetorically. “I question the wisdom of anybody who wants to speak out this early in the process.—

Scott Mulhauser, Baucus’ spokesman on the Finance Committee, was more subtle, but still hammered home the point. “Sen. Baucus is confident health care stakeholders will continue to play a constructive role in the health care reform effort. These groups know the train is leaving the station.—

In fact, the Washington-savvy heads of the big health care associations want to keep their seats at the negotiating table.

But it’s not their decision alone. Some of their member companies are starting to worry that keeping quiet will only make matters worse.

Andy Rosenberg, a Democratic lobbyist at Ogilvy Government Relations who has several health care clients, said health associations are feeling the pressure from their member companies.

“A potential challenge looms for the Washington leadership of these trade associations,— Rosenberg said. “How do they maintain their relationships and commitment to a process and what happens if, when the details come out, their membership isn’t convinced that the process is worth participating in.—

A senior Democratic lobbyist who represents health care clients said that health insurance, hospital and provider groups are going to start ramping up their messaging efforts, especially to expose their concerns with the public plan option, which many fear would undercut private insurers.

And that isn’t the only sticking point: Hospitals, for one, could peel off if they face cuts that could amount to as much as $250 billion over the next decade.

“Doctors, hospitals and insurers are equipped and stand ready and are very well-positioned to be extremely helpful in pushing legislation through or coming out against it,— a second health care lobbyist said.

For several months, Baucus and Sen. Edward Kennedy (D-Mass.), the chairman of the Health, Education, Labor and Pensions Committee, led simultaneous negotiations on a reform bill that — given the politics of the issue — were considered remarkably bipartisan. Baucus has worked closely with Finance ranking member Chuck Grassley (R-Iowa), and Kennedy has done the same with HELP ranking member Mike Enzi (R-Wyo.).

Similarly, discussions with the business community and insurance industry were notably amicable and cooperative. Representatives of both have been at the negotiating table from the beginning.

But cracks in this façade have begun to emerge over the past few weeks — both on Capitol Hill and downtown.

Democrats, mindful of the political breakdown in Congress and revolt in the business community that defeated the push for health care reform in 1993, are hopeful that history doesn’t repeat itself.

“I would just hope that those who have vested interests in reform — whether it’s the business community, whether it’s the labor unions, whether it’s provider groups or hospitals or doctors or advocacy groups for different illnesses — that they will wait to see what the final product looks like before they start trying to run their ads,— Sen. Benjamin Cardin (D-Md.) said Monday. “Because I think if you start to do that, there could be almost a race to see how many ads you can get up on so many different points without looking at the full picture.—

Congressional Republicans have placed particular emphasis on the government-run, public plan option supported by Obama and Democratic Congressional leaders. The GOP believes this proposal would diminish the quality of care and lead to medical rationing. The business community is equally concerned, but is growing even more worried about the costs of reform and is nervous that it might be slapped with the bill.

Republicans view an upheaval by the business community as their only chance to win the health care battle.

Senate Minority Leader Mitch McConnell (R-Ky.) has used his opening floor remarks for the last five business days to push the Republicans’ message on health care. He acknowledged on Monday that it would be helpful to the GOP’s cause to get help from the outside and encouraged anyone who shares his opposition to the public plan option and other problematic health care proposals to voice their opinions.

“I think it’s important to hear from people who are out in the country who are going to be affected by the idea that the government would adopt a plan here from which no one is going to be able to compete. People who think that’s a bad solution ought to speak up,— McConnell said.

“I think now’s a great time to do it, we’re moving into this debate in a major way and we need to hear from our constituents who may have a contrary view to that of the administration.—

Some Republicans are sympathetic to the business community’s silence thus far, noting that GOP Members have only recently spoken and that it is only natural to wait for details before raising the volume of opposition.

But not all Republicans are as understanding, with some downright critical of the business community’s decision to maintain silence even as Democratic leaders write legislative language and prepare for bill mark-ups in Finance and HELP set to occur in the next few weeks.

“There is significant frustration with the business community for not speaking out against the sharp tax increases they will face to pay for government-run health care,— said one Senate Republican leadership aide. “These tax increases will be passed along to consumers and negatively impact job creation. The business community really has their head in the sand on this one.—