The chairman of the Senate's Health, Education, Labor and Pensions Committee was adamant on Thursday that only Democrats  take part in the chamber's effort to merge its two distinct healthcare proposals.

That final product, added Sen. Tom Harkin (D-Iowa), would include a strong public option -- a provision that's part of the HELP committee's plan, but is otherwise absent from the Senate Finance Committee's forthcoming bill.

“No, this will be a proposal by the Democrats to bring a bill on the floor," Harkin told reporters during Thursday's teleconference. "And that’s what I have said before, that the people of this country — I keep saying — the people of this country pretty overwhelmingly elected Barack Obama last fall and to make changes."

“We will have a bill on the president’s desk before Christmas, a health-reform bill," he added. "It will have a lot of good stuff in it. It will have a lot of prevention and wellness programs in there that I’ve been fighting for."

Harkin's unequivocal remarks arrive at a tense moment during the Senate's healthcare negotiations. While the HELP committee chairman is working diligently to shore up support for the beleaguered public option, his counterpart on the Finance Committee is struggling to complete the markup process without losing almost every Republican vote -- an outcome that has seemed increasingly more likely by the day.

It is unclear whether Baucus supports Harkin's stated refusal to invite Republicans to the merging table, an effort that likely will not take place for at least another two weeks. However, the mere suggestion of the party's exclusion is sure to anger the Senate's most vocal Republicans, who have recently ramped up their criticism of the Democrats' healthcare reform strategy.

"We won't have a bipartisan bill because the White House stepped in here two weeks ago and demanded that [Chairman Max Baucus (D-Mont.)] break off his talks with the Republicans," Sen. Chuck Grassley (R-Iowa), the committee's ranking member, told reporters earlier on Thursday. "I don't think Senator Baucus wanted to do that. And there was still some very key differences between the two sides."