Sen. Joe Lieberman (I-Conn.) said he might not be the only Democrat to oppose cloture for final passage of the healthcare bill.
Lieberman said he would vote with Democrats over the weekend to proceed with debate on the Senate health bill, but said that if the final version includes a public option, other Democrats would join him to filibuster it.
"If at the end of the debate, I think the bill is overloaded, will add to taxpayers' premiums, et cetera, particularly with this government-sponsored public insurance company, I'm not going to vote for cloture," Lieberman said, reiterating a threat to join a filibuster of the Senate bill.
"And I believe I'm not going to be the only one -- not the only member of the Democratic caucus," Lieberman added during an appearance on Fox News.
Senate Majority Leader Harry Reid (D-Nev.) said Thursday that he would bring up a motion to proceed, which will start the health debate, this Saturday. Signs out of the Senate have pointed toward all Democrats, including Lieberman, voting for that debate to begin.
But a handful of Democrats could still block final passage on the bill because of its public option, which allows states to opt-out of establishing a government-run insurance company.
Centrist Democrats whose position on allowing a vote for final passage are up in the air include Sens. Ben Nelson (Neb.), Mary Landrieu (La.), Evan Bayh (Ind.), and Blanche Lincoln (Ark.).
By contrast, Sen. Tom Harkin (D-Iowa), the chairman of the Senate Health, Education, Labor and Pensions (HELP) Committee, said Wednesday evening that he's confident that all Democrats -- including Lieberman -- will stick together on final passage of the health bill.
Lieberman has long said that Democrats could accomplish the substance of health reform without the public option.