With a critical decision looming on the shape of the public insurance option in the House health care overhaul, Speaker Nancy Pelosi (D-Calif.) is scrambling to find the votes for a version that hews as closely as possible to what liberals in her Caucus have demanded.

Moderate Democrats have thrown up roadblocks to a so-called robust public plan — under which a government insurance program would pay hospitals at the same discount rates as Medicare ­— in part because they contend it would put an unsustainable squeeze on rural hospitals, which they say suffer from unfairly low reimbursements.

So Pelosi on Wednesday rolled out a compromise meant to win over enough of them to put the provision over the top. The revised proposal bumps payments to hospitals under the plan from flat Medicare rates to 5 percent above them.

“What we’re trying to do is work through various different issues that individual Members have indicated problems with because we want to make sure it works for their areas and their people,— House Majority Leader Steny Hoyer (D-Md.) said.

But it was not clear the change would budge any holdouts and bring the Speaker closer to the consensus that has eluded her.

During the Wednesday morning huddle, convened with a capacity crowd of lawmakers in Pelosi’s conference room, at least one leading Blue Dog Democrat concerned about rural hospitals spoke up to make clear the tweak would not win his support. “Those areas most underpaid under Medicare can’t accept expanding the universe of patients at Medicare rates,— Rep. Earl Pomeroy (D-N.D.) said in an interview.

It’s a familiar conundrum for Pelosi: how to split the difference between what she feels is the best public policy and a more moderate approach pushed by her most politically vulnerable Members. Many of those lawmakers are still smarting from a tough July vote on climate change legislation that landed with a thud in the Senate. And they are growing increasingly concerned that they will once again be forced to take a difficult vote on a public plan that returns from conference negotiations heavily watered down — if it survives at all. “I’m not sure she can’t pull it through, but the amount of pain on the floor will make energy look like a cakewalk,— one senior Democratic aide said.

Leaders are still hunting for votes, but a decision is fast approaching: Democrats hope to bring a bill to the floor the first week of November.

Pelosi spokesman Nadeam Elshami said while the final form remains up in the air, “the bottom line is this: The House bill will have a public option to bring competition to the insurance industry and ensure affordability for the middle class.—

On top of a robust public plan, leaders are mulling two versions that would instead rely on reimbursement rates the federal government would negotiate with providers. Under one option, the public plan would start with negotiated rates but fall back on payments pegged to Medicare if premiums rise too quickly; the other would use negotiated rates while moving more people into Medicaid.

Rep. Raúl Grijalva (D-Ariz.), a co-chairman of the Congressional Progressive Caucus who has led the charge for a robust public plan, said he would support the change in hospital payments if it meant preserving the kind of plan liberals have demanded. “If this moves it down the road, OK,— he said.

Grijalva said liberals are angling for the strongest possible version of the provision in anticipation of a conference showdown against a Senate bill that lacks a public plan. “Being a realist and fighting for this public option, the machinations in conference are going to produce something different,— he said.

At stake is the public option itself, Grijalva said. He contended that if House Democrats adopt a plan pegged to Medicare rates, the final bill will include some version of a public plan. But if the chamber opts instead for negotiated rates, the plan won’t survive conference negotiations.

That logic has set Blue Dogs to howling. They have repeatedly contended they should not be forced to take a politically treacherous vote on what they view as a bad bill simply to preserve negotiating leverage with the Senate.

Pomeroy said Pelosi is in line with the majority of her Caucus in backing a robust public plan. “But not a majority of the House. They’re still looking for 218 votes.—

On that point, Pomeroy and Grijalva agree. “I think she’s in a difficult position,— Grijalva said.