Top aides to Senate Finance Chairman Max Baucus ( D-Mont.) held a private meeting on Monday with a bloc of prominent Democratic lobbyists, warning them to hold their fire or be left out of negotiations on President Barack Obama’s No. 1 legislative priority.

Russell Sullivan, the top staffer on Finance, and Jon Selib, Baucus’ chief of staff, sat down with the group of about 25 stakeholders, including several former Baucus aides. The meeting, held in the Hart Senate Office Building, was designed to give the lobbyists a preview of a proposal by Baucus and Finance ranking member Chuck Grassley (R-Iowa) for how to pay for a massive health care overhaul.

According to sources familiar with the closed-door session, Sullivan and Selib made clear that lobbyists who want to be involved in health care reform going forward need to keep their complaints to themselves. A Baucus Finance Committee spokeswoman described it as an opportunity to keep stakeholders informed and pre-empt a mutiny.

One participant said Selib and Sullivan “made a very strong appeal for people to remain constructive.—

Baucus, who is leading Senate efforts along with Sen. Edward Kennedy (D-Mass.) to craft a Senate health care bill, has been holding working-group meetings on the issue, and he is counting on his downtown Democratic allies to ensure the package moves ahead. Senate Democrats are hoping to have a bill on the floor by August and to the president this year.

Paying for health care reform has emerged as one of the biggest sticking points for lawmakers, and Baucus has been working closely with Grassley to explore the issue in a bipartisan way. The duo has been working hand-in-glove on the subject generally, hoping to avoid the partisan pitfalls that sank health care reform under former President Bill Clinton.

With that in mind, Baucus’ chief concern has been to ensure that any heartburn over the emerging policy options does not morph into a full-scale campaign against the deal he is trying to reach with Republicans.

“Chairman Baucus wants to keep health care stakeholders informed of his progress on health reform,— Finance Committee spokeswoman Erin Shields said. “This is a big, transformative process. It’s too important to get caught up in one detail or another. Sen. Baucus wants to keep everyone at the table and keep everyone working together.—

Senior Democratic lobbyists at Monday’s closed-door meeting included former Baucus Chief of Staff Jeff Forbes of Cauthen Forbes & Williams; Larry O’Brien III of the OB-C Group; Michael Levy of Brownstein Hyatt Farber Schreck; David Castagnetti of Mehlman Vogel Castagnetti; Jonathon Jones of Peck, Madigan, Jones & Stewart and Rich Tarplin of Tarplin Strategies.

Sullivan and Selib also met with associations with vested interests on the proposal Monday.

Sources familiar with the lobbyist meeting described it as collegial, but they said Baucus’ aides made clear that any public opposition to the proposed financing of a reform package would be at their clients’ peril. The staffers’ message to K Street was clear: Tell your clients to let the process work and don’t torpedo it with advertisements, press releases and Web sites.

The decision to proactively meet with the lobbyists isn’t being made in a vacuum. Baucus, Democratic Senate leaders and Obama are hoping to bring stakeholders in early to avoid a repeat of Clinton’s failed 1993 effort. Clinton, along with then-first lady Hillary Rodham Clinton, was roundly criticized for negotiating a plan with a small group of insiders and expecting Congressional and downtown buy-in.

A senior Democratic Senate aide said Baucus’ directive to the health care lobbyists and other stakeholders did not originate from the Senate Democratic Conference’s leadership team. But this aide suggested that Baucus’ approach has leadership support.

“I think they are trying to be as inclusive as possible and are trying to make it clear that they have an open door,— said William Signer of the Carmen Group, who was at the meeting.

Sources also indicated that the Baucus aides laid out the expected timetable for the bill, saying Baucus would like to mark it up in June to meet the August floor deadline.

“They told us we need to give Senators some space to roam,— said another lobbyist in the meeting.

Others in the room concurred.

“Basically, they were saying, Tell your clients that if they are smart, they will play this process the right way, but it doesn’t mean cutting deals necessarily,’— said yet another Democratic lobbyist from the meeting.

David M. Drucker contributed to this report.