PORTLAND -- There may be strong desire on Capitol Hill to get a health reform bill passed by year's end, but Maine's senior senator has her doubts, calling that goal "very ambitious."

Sen. Olympia Snowe reiterated one of her key positions Friday, saying she won't support a Senate bill that contains a public option.

Senate Majority Leader Harry Reid, D-Nev., has merged two bills crafted by the Senate's Health and Finance committees. The details of that bill are not yet public, though Reid has said it includes a public option for health insurance with an opt-out provision for states that don't want to participate.

Snowe said she will continue to work on any bill that the Senate considers. She again suggested her alternative to a full government-backed plan: a fallback, safety-net plan that would be triggered in states where insurance companies fail to offer affordable plans.

Snowe, who was in Maine on Friday, met with the editorial board of MaineToday Media. She noted that the nearly 2,000-page House health care bill is due before that body next week.

While the House wouldn't consider amendments to its bill, that wasn't the case in the Senate, she said.

Both the Finance and Health committee bills had almost 600 amendments, Snowe noted. The merged bill may contain as many as 2,000 amendments from the full Senate, she said.

President Obama and Democratic leaders have said they would like to get a bill finished this year. Snowe said she thinks that means a complete bill out of Congress -- not just a Senate version.

"I just think it's going to be very difficult to get it done by Christmas," she said.

Snowe said it would take at least 60 votes in the Senate to remove the public option from the bill, which would be difficult; and the majority party appears to have the numbers to move the bill forward without help from Republicans.

"The question is how they want to drive this philosophically," Snowe said.

To Obama's credit, she said, he was willing to work for a bipartisan solution, as was Finance Committee Chairman Max Baucus, D-Mont.

Even though she has been the only Republican to support one of the bills, Snowe said, that doesn't mean other GOP senators might not follow suit as the process moves forward.

Snowe said she hopes Democrats still will value Republicans' input and not "jettison that entirely."

"If I were in their shoes, I would want to make sure I get the very best product. That's what I'll continue to contribute, irrespective of where I come down on the final bill or where it is -- I will try to make it better," Snowe said. "If it becomes law, I want to make sure I can get as many good ideas in there as possible. That's my obligation, and I'll continue to do that."

Snowe said the Congressional Budget Office has determined that the threat of a safety-net trigger such as what she has proposed would be enough to drive down costs in the insurance industry. That would be better than imposing a government-run plan on the market, she said.

"Introducing a government approach in an already dysfunctional market would truly threaten the ability to create a competitive market," Snowe said. "I want the private sector to be able to work if it can. If it can't, and we want to hold the industry accountable, you do that with the threat of the trigger."

Snowe said that what has happened in the insurance industry has been "unconscionable."

Over the last decade, she said, insurance premiums alone have risen 131 percent, compared with wages at 38 percent and inflation at 28 percent.

"That's the challenge we face in America today. We can put our heads in the sand and pretend it's going to go away," Snowe said, but "it's not going to go away -- it's going to grow exponentially worse."